WO2000038218A2

WO2000038218A2 - Device and method for treating substrates

Info

Publication number: WO2000038218A2
Application number: PCT/EP1999/008853
Authority: WO
Inventors: Wolfgang Kroeber; Joachim Pokorny; Andreas STEINRÜCKE
Original assignee: Steag Microtech Gmbh
Priority date: 1998-12-22
Filing date: 1999-11-18
Publication date: 2000-06-29
Also published as: WO2000038218A3; TW447034B

Abstract

A device and method for treating substrates, especially semiconductor wafers, used to expel gas bubbles that are enclosed in a substrate. The inventive device comprises a process container with a container wall and a substrate holder that is movably arranged above the process container, whereby one edge of the container wall located opposite to the substrate has an inner circumference that becomes wider towards the outside. Treatment liquid is directed to an outer area of the substrate. The device for treating substrates comprises a container that can be filled with treatment fluid, an overflow that surrounds the container and a substrate holder for positioning a substrate above the container. A control device that regulates the level of the treatment fluid in the overflow on the basis of the distance between the substrate holder and the container makes it possible to treat the substrate in a more homogeneous manner in said device.

Description

Device and method for treating substrates

The present invention relates to an apparatus and a method for treating substrates, in particular semiconductor wafers, with a process container having a container wall and a substrate holder which is movably arranged above the process container and which positions the substrate above the container wall.

Devices of this type are known in the semiconductor industry for a wide variety of treatment processes. In these devices, a treatment fluid is generally passed onto a substrate arranged on the substrate holder. In this case, the flow to the substrate is essentially perpendicular to a substrate surface. In some cases, especially where a treatment fluid outlet is deeper than the flowed substrate surface, gas bubbles are trapped beneath the substrate, which impair good, uniform treatment of the substrate. The uniform treatment can also be disrupted by a stall on a substrate surface spaced above the process container.

A device of the type mentioned is known for example from US-A-5,000 827. In this device, a semiconductor wafer is held above the process container by means of a multiplicity of support members on which the afer rests and flowed from below with a treatment fluid which flows over an edge of the process container through a gap formed between the substrate and the process container wall. The problem arises here that in particular in a gas bubbles are trapped beneath the substrate, adjacent to an edge of the substrate receiving element, which impair good and uniform treatment of the substrate.

The object of the present invention is to ensure a good and uniform treatment of substrates. A special task is to flush out gas bubbles trapped beneath a substrate before and / or during treatment of a substrate.

According to the invention, this object is achieved by a device of the type mentioned above, in which an inner circumference widening outwards is provided for an edge of the container wall facing the substrate. Due to the outward widening inner circumference of the edge of the container wall facing the substrate, a flow of the treatment fluid is directed towards edge areas of a substrate located above it, in order to avoid areas of relative flow calmness there. This ensures a good flushing out of gas bubbles and a good, even treatment even in an area outside the inner dimensions of the container wall.

According to a particularly preferred embodiment of the invention, the substrate with the substrate holder can be positioned at different distances above the edge of the container wall, so that a flow channel formed between the substrate and the container or the substrate holder and the container can be changed. By changing the flow channel, the flow rate can be changed in a simple manner and can be used for flushing out. len of gas bubbles can be increased. Advantageously, the edge of the container wall in a position of the substrate is directed at a contact area between the substrate holder and the substrate in order to avoid that a relative calm flow occurs in this area. In this position, the distance between the substrate and the edge of the container wall is the smallest possible distance, ie the substrate cannot be lowered deeper in order to achieve particularly high flow rates and a good flushing out of gas bubbles.

Advantageously, the thickness of the container wall tapers towards the edge in order to allow the opening of the process container to overlap as much as possible with the substrate above, while at the same time forming a sufficient flow channel between a part of the substrate holder surrounding the edge and the edge. The taper is advantageously formed by contouring the outer circumference of the container wall in order to form a sufficient flow channel between the part of the substrate holder and the container wall. The contouring of the outer circumference of the container wall is advantageously adapted to an inner circumferential shape of a carrier ring of the substrate holder in order to prevent the flow channel formed between them from changing too suddenly and the flow tearing off.

According to a particularly preferred embodiment of the invention, the device has an anode arrangement arranged inside the process container in order to apply a voltage between the substrate and the anode arrangement in order to promote the treatment process. Doing so the anode arrangement is advantageously formed by a perforated plate or an expanded metal.

To generate a voltage between the substrate and the anode arrangement, a contact arrangement is advantageously provided on the substrate holder which, according to a particularly preferred embodiment of the invention, makes electrical contact with a surface of the substrate facing the process container.

For a homogenization of the flow of the treatment fluid within the process container, the latter has a funnel-shaped base which widens towards the substrate and which, according to one embodiment, is formed by an insert. Alternatively, the funnel-shaped bottom could be formed in one piece with a vertical container wall. According to a particularly preferred embodiment of the invention, the funnel-shaped bottom forms part of the container wall.

For a further homogenization of the flow of the treatment fluid within the process container, at least one perforated plate is provided between a bottom of the process container and the edge of the container wall of the process container facing the substrate.

In a further embodiment of the invention, an overflow collar surrounding the process container is provided, which advantageously has an upwardly open space between the container wall of the process container and the

Overflow collar forms. A treatment fluid can be accumulated outside the process container in a particularly simple manner by means of the overflow collar. The over- Running collar preferably higher than the edge of the container wall facing the substrate, so that the treatment fluid can be dammed up to a level which is at or above the height of the edge of the container wall facing the substrate. A drain is preferably provided in the overflow collar in order to drain the treatment fluid accumulated therein.

According to a preferred embodiment of the invention, a further process container surrounding the process container is provided to collect the treatment fluid used. The additional process container enables the treatment fluid used to be collected and possibly recycled.

According to a particularly preferred embodiment of the invention, the device is used as a metal plating device.

The above object is also achieved by a method for treating substrates, in particular semiconductor wafers, in which a substrate is moved into a first position above and at a distance from a container wall of a process container by means of a substrate holder, and a treatment fluid through the Process container is directed to a surface of the substrate facing the process container, wherein the treatment fluid is directed towards an outer region of the substrate via an outwardly widening inner peripheral surface of an edge of the container wall of the process container facing the substrate. In this way, as already stated, it is prevented that in edge regions of the substrate A relative calm flow occurs to ensure a good flushing out of gas bubbles.

According to a further embodiment of the invention, the substrate is advantageously raised into a second position which is further spaced from the edge of the container wall of the process container. This lifting of the substrate leads to an enlargement of the flow channel formed between the substrate and the substrate carrier on the one hand and the process container on the other hand, in order after the flushing out of gas bubbles for a further treatment of the substrate a low flow speed and a more uniform flow between the inner and outer regions of the To provide substrate.

In a particularly preferred embodiment of the invention, a voltage is applied between an anode arrangement located in the process container and the substrate in order to promote the treatment of the substrate. The surface of the substrate facing the process container is advantageously electrically contacted. For good process control, the applied voltage is changed depending on the position of the substrate. The applied voltage in the second position of the substrate is advantageously higher than in the first position. This has the advantage that, for example, deposition of a material on the substrate in the first position, in which the flow velocity is higher than in the second position, is prevented.

Advantageously, the flow directed onto the substrate is homogenized within the process container in order for a good and even treatment of the substrate to provide a homogeneous flow. The homogenization is advantageously achieved via a funnel-shaped bottom of the process container and / or at least one perforated plate arranged in the process container. Advantageously, during the blowing out of air bubbles in the first position, a drain is opened in an overflow collar surrounding the edge of the process container, so that the treatment fluid can flow off freely and the blowing-out flow is not opposed. In the second position of the substrate, however, the drain is advantageously closed in order to achieve an accumulation of treatment fluid. The treatment fluid is advantageously dammed up until it reaches a height that is at least at the height of the raised substrate in order to ensure good contact between the treatment fluid and the substrate.

The object underlying the present invention is achieved in a device for treating substrates with a container which can be filled with treatment fluid, an overflow surrounding the container and a substrate holder for positioning a substrate above the container in that a control device for controlling a treatment fluid level in the Overflow is provided depending on the distance of the substrate holder from the container. The control device enables the treatment fluid level in the overflow to always be at or above the level of the substrate. This ensures good contact between the treatment fluid and the substrate and prevents the flow directed towards the substrate from being torn off, in particular when the distances between the substrate and the container wall are greater. In one embodiment of the invention, the control unit has a controllable outlet valve in the overflow, via which the treatment fluid level can be adjusted. Advantageously, a further overflow is arranged adjacent to the overflow, so that the treatment fluid level in the overflow is limited to the further overflow in a simple manner by the height of the overflow edge. In this case, a height-adjustable overflow rim is preferably provided in order to provide different treatment fluid levels in the overflow in a simple manner.

In a preferred embodiment, a floating body has the overflow edge. Due to its natural buoyancy, the floating body enables a particularly simple possibility of adjusting the height of the overflow edge.

In an alternative embodiment, a slide having the overflow edge is provided, via which the height of the overflow edge is adjusted. The slide is preferably biased upwards by means of a spring and is easily adjustable against the spring preload.

A spacer is preferably provided between the floating body or the slide and the substrate holder, which specifies a predetermined distance between the floating body or the slide and the substrate holder. This results in a particularly simple possibility of setting the height of the overflow edge and thus the treatment fluid level directly via the movement of the substrate holder. In particular, this creates a fixed, essentially constant relationship between the Maintain the height of the overflow edge and the height of the substrate holder.

The object is achieved in a method for treating substrates with a treatment fluid, in which a substrate with a substrate holder is held over a basin surrounded by an overflow and flowed with the treatment fluid from below, in that the level of the Treatment fluid in the overflow is controlled depending on the distance between the substrate holder and the basin. The advantages already mentioned result from this method.

The device is described below on the basis of preferred exemplary embodiments with reference to the figures. Show it:

FIG. 1 shows a schematic cross-sectional view of a device according to the invention for treating substrates; Figure 2 is an enlarged partial view of the device according to the invention; and

FIG. 3 shows a further enlarged partial view of a pot edge contour of a process container of the present invention; Figure 4 is a schematic cross-sectional view of an alternative embodiment of the device according to the invention;

FIGS. 5 and 6 are schematic cross-sectional views of a further exemplary embodiment of the device according to the invention in different treatment positions;

Figures 7 and 8 are schematic cross-sectional views of yet another embodiment of the device according to the invention in different treatment positions. FIG. 1 shows a metal plating device 1, in particular a copper plating device, with a substrate holder 2 and a process container 3. The substrate holder 2 consists of an upper cover 5 and a lower ring 6, between which a wafer 7 is clamped. The substrate holder 2 can be raised and lowered vertically above the process container 3. As can be seen in FIG. 3, a seal 9 is provided on an inner circumference of the ring 6 and is arranged concentrically around a center point of the wafer 7. The seal 9 seals an edge region of the wafer 7. This edge area of the wafer 7 is contacted via a plurality of contact springs 11, one of which can be seen in FIG. 3.

For further details regarding the substrate holder, in order to avoid repetition, reference is made to the application filed on the same day by the applicant of the present application with the application number 198 59 467.4 and the title “substrate holder”. In this respect, this application is made the subject of the present application.

The process container 3 has a base plate 15 and side walls 16. A line 18 is formed in the base plate 15, which is connected at one end via an opening 20 to a space formed between the side walls. The line 18 is connected to a source of a liquid electrolyte via a connecting piece 22 connected to the line 18 and lines not shown. One end of the line 18 spaced from the opening 20 is closed by a stop fenelement 24 closed, which is attached to a rod 26. By moving the plug 24, one end of the line 18 can be opened and the electrolyte in the line 18 can be drained into a container (not shown) surrounding the process container 3.

A funnel element 30 is arranged between the side walls 16 and spaced apart from the base plate 15 and is fastened to the side walls 16 in a suitable manner, such as, for example, screws. A chamber 32 is formed between the base plate 15 and the funnel element 30. The funnel element 30 has a centered opening 34 facing the chamber 32 with a small diameter. Starting from the opening 34, the funnel element 30 forms a funnel-shaped space 36 that widens upward. Above the funnel-shaped space 36, a perforated plate 38 is provided which is in contact with an upper edge 39 of the funnel element 30. The perforated plate 38 rests on the upper edge 39 of the funnel element and is fastened to the side walls 16 in a suitable manner, for example by screws 40. An upper wall part 44 is fastened on an end face 42 of the side wall 16 opposite the base plate 15. The wall part 44 has openings 46 for the passage of electrical contact elements 48. The contact elements 48 are in electrical contact with an anode plate 50 located above and spaced apart from the perforated plate 38, which is also designed as a perforated plate. Alternatively, the anode plate 50 can be designed as an expanded metal. As can best be seen in FIGS. 2 and 3, the wall element 44 has a contoured inner peripheral surface 52. The inner peripheral surface 52 is inclined in a lower region with respect to a longitudinal central axis. In a further region located above, the inner circumferential surface 52 is essentially parallel to the longitudinal central axis. In an upper edge region 54, the circumference of the inner circumferential surface 52 increases due to an outwardly curved rounding 55. In the edge region 54 of the wall element 44, the wall thickness of the wall element 44 tapers upwards to a tip 56, as can best be seen in FIG. 3 . The taper is achieved by a bevelled outer contour 58 in the edge region 54 of the wall element 44. This outer contour 58 is adapted to an inward-pointing contour of the seal 9 of the substrate holder 2.

An overflow collar 60, which surrounds the wall element 44, is attached to the wall element 44. The overflow collar 60 forms an upwardly open space 62 between it and the wall element 44. A controllable drain 64 is formed in a side wall of the overflow collar 60 and can be opened and / or closed as described below. The side walls of the overflow collar 60 are higher than the uppermost tip 56 of the wall element 44.

During the operation of the device according to the invention, the substrate holder 2 is first lowered to such an extent that the wafer 7 is located just above the tip 56 of the wall element 44. In this position, the first step is to introduce a liquid electrolyte, which consists, for example, of water, sulfuric acid, copper sulfide, chlorine, sodium chloride and organic additives, air blown out by the bell shape of the substrate holder below the substrate is blown out. The distance between the tip 56 and the substrate -7 is relatively small in order to achieve high flow speeds. Due to the outward widening inner circumference of the wall element 44 in the edge region 54, part of the flow is directed directly at the transition between the sealing lip 9 of the substrate holder 2 and the wafer 7. Due to the contour 58 of the outside, the flow cross section in a region behind the tip 56 of the wall element 44 is kept as uniform as possible over a short distance in order to prevent the flow from breaking off in this region, thereby ensuring good air blowing out. After air has been blown out, the substrate holder 2 is raised somewhat, since given the small distance between the substrate 7 and the tip 56, the flow rate would be too high for a homogeneous deposition of metal on the substrate, in particular in this area. When the substrate holder is raised, liquid electrolyte is accumulated in the overflow collar 60 at the same time as the overflow 64 is closed, so that the cover is at least partially absorbed in the liquid. The liquid level is raised to the level of the wafer or beyond to ensure that the contact between the electrolyte and the wafer does not break due to the increased distance. The distance between substrate 7 and tip 56 can be adjusted depending on the desired flow conditions for the deposition.

Even while air is being blown out, a small current is drawn between the anode plate 50 and the created the surface of the wafer 7. This is necessary so that a thin metal layer previously applied to the surface of the wafer 7 is not etched or dissolved by the electrolyte. However, the voltage applied here is not sufficient to achieve a substantial deposition of metal on the wafer 7. In the raised position of the substrate holder, the current is then increased in order to cause metal to be deposited on the wafer 7.

FIGS. 4 to 6 show an alternative metal plating device 100 which has an essentially three-part process container, with not all details being shown in FIGS. 5 and 6 to simplify the illustration. The device 100 has a funnel element 102, a container wall 104 attached to it and a collecting container 106.

The funnel element 102 has a funnel 108 which widens upwards. A lower opening 109 of the funnel 108 is closed by a connection element 110, via which treatment fluid is introduced into the funnel 108. The connector 110 is attached to the funnel 108, for example, by welding or some other technique known in the art. A support element 112, at least partially surrounding the funnel 108, is attached to the outer circumference of the funnel 108.

In an upper region 114, the funnel 108 has a greatly broadened wall thickness. In this area 114 at least one through opening 116 is provided for receiving or carrying through a contact pin 118, which will be described below. Furthermore, a passage opening 120 is provided in the area 114, at the lower end of which a connection element 122 is attached. A bore 124 is also provided in area 114. This serves to receive a fastening screw 126, for fastening the container wall 104 to the funnel element 102, as will be described in greater detail below.

The upper container wall 104 is covered by an inner wall

128 and an outer overflow collar 130 are formed. In an upper edge region, the inner container wall 128 is contoured in exactly the same way as the container wall 44.

In the circumferential direction, the container wall 128 has three thickenings 131, one of which can be seen in FIG. 4. In the thickened portions 131 of the container wall 128 there are bores 132 for receiving set screws 134 which extend into openings in the lower ring 6 of a substrate holder 2 and serve as a support for the lower ring 6. The height and orientation of the substrate holder 2 located above the process pot can be precisely adjusted and, if necessary, also changed using the adjusting screws 134. Instead of adjusting screws, sliding cylinders, spindles etc. could also be used.

A substantially U-shaped, upwardly open chamber 140 is formed between the inner container wall 128 and the overflow collar 130. The overflow collar 130 surrounds the inner container wall 128 and is higher than this. In the bottom of the chamber 140, an opening 142 is formed, as well as a stepped bore 144, which is used for partially receiving and passing the screw 126. The trich The terelement 102 and the container wall 104 are fastened to one another by the screw 126, which extends through the opening 144 in the container wall into the opening 124 in the funnel element. The openings 144 and 124 for receiving the screw 126 are aligned with each other. The openings 142 and 120 are also aligned with one another in order to form an outlet for the chamber 140 via the connection element 122.

During the screwing together of the funnel element 102 and the container wall 104, a perforated plate 150 is clamped in between in suitably designed recesses. Furthermore, when screwing together, an upper side of the pin 118 extending through the widened region 114 of the funnel 108 is clamped against a lower side of a contact element 152 of an anode plate 154. This enables electrical contacting of an anode plate 154 located inside the process container from outside the process container. A collecting container 106 is attached to the outer circumference of the widened region 114 of the funnel 108, such as, for. B. by welding. The collecting container 106 surrounds a part of the funnel 108 and the upper container wall 104, the collecting container 106 having a wall which is higher than the overflow collar 130 of the container wall 104. Between the overflow collar 130 of the container wall 104 and the collecting container 106 a substantially U -shaped, upwardly open chamber 160 is formed, which has an opening, not shown, to which a connecting element 162 is attached.

The operation of the device according to this exemplary embodiment is described below with reference to FIGS. 5 and 6. wrote. The substrate holder is brought into the position shown in FIG. 5 with a substrate held therein, so that a narrow gap is formed between a substrate held on the substrate holder and an upper edge of the container wall 128. Subsequently, liquid electrolyte is introduced via the funnel element 102 until it flows into the chamber 140 through the above-mentioned gap between the substrate and the upper edge of the container wall 128. Due to the relatively small gap, air, which is enclosed by the bell shape of the substrate holder below the substrate, is blown out, as in the first exemplary embodiment. A valve 170 connected to an outlet of the chamber 140 is opened in order to ensure a good drainage of the overflowing electrolyte, so that there is no resistance to the flow in the region of the above-mentioned gap.

Subsequently, the substrate carrier is raised to the position shown in FIG. 6 and the valve 170 is closed, so that the one flowing into the chamber 140 flows

Electrolyte accumulates there. The electrolyte is dammed up until it flows into the outer chamber 160 via the outer overflow collar 130. As a result, the level of the treatment fluid in the chamber 140 is raised so that it lies at the level of the substrate from which flow flows from below. This ensures reliable contact between the treatment fluid and the substrate, which could otherwise break off when the substrate carrier is lifted.

FIGS. 7 and 8 show a further exemplary embodiment of the present invention. The exemplary embodiment of FIGS. 7 and 8 is essentially the same as that Embodiment of Figures 4 to 6 and therefore the same reference numerals are used in the following.

FIGS. 7 and 8 show a metal plating device 100 which, as in the exemplary embodiment according to FIGS. 4 to 6, has an essentially three-part process container. The process container has a funnel element 102, a container wall 104 attached to it and a collecting container 106. The container wall 104 is formed by an inner wall 128 and an outer wall 130 '. In contrast to the exemplary embodiment in FIGS. 4 to 6, in which the outer wall 130 was higher than the inner wall 128, in the exemplary embodiment in FIGS. 7 and 8 the outer wall 130 ′ is lower than the inner wall 128. Between the inner wall 128 and the outer wall 130 'forms a generally U-shaped, upwardly open chamber 140.

A height-adjustable overflow element is arranged within the chamber 140. FIGS. 7 and 8 each show two different overflow elements, namely an overflow element designed as a floating body 180 on the left side and a spring-loaded slide 182 on the right side. Although two different height-adjustable overflow elements are shown in FIGS. 7 and 8, it should be noted that in the actual implementation a uniform overflow element is provided, which is designed either as a floating body 180 or as a spring-loaded element 182. Of course, it is also possible to additionally pretension an element designed as a floating body by means of a spring. The floating body 180 will now be described in more detail below. The floating body 180 extends around the chamber 140 and is guided on the inner circumference of the outer wall 130. The floating body 180 forms an internal chamber 184 which is essentially rectangular in cross section and is closed. The closed volume of the chamber 184 generates the necessary buoyancy of the floating body 180 in a fluid. The floating body 180 has an overflow flange 186 which extends upwards and tapers upwards to an overflow edge 188. The overflow flange 186 has an inner circumference that is larger than the outer circumference of the substrate carrier 2, so that it can be received radially in the overflow flange 186.

The floating body 180 also has a spacer 190 in the form of a web, which is arranged within the inner circumference of the overflow flange 186 and is contacted by an underside of the substrate carrier 2, as shown in FIGS. 7 and 8. When the chamber 140 is filled with treatment fluid, the float 180 floats in the chamber until the spacer 190 comes into contact with the underside of the substrate carrier 2. The overflow flange 186 extends radially around the substrate holder 2 and forms an overflow edge 188 which lies essentially on the same plane as a substrate accommodated in the substrate holder 2. The overflow edge 188 is in height above an upper edge of the outer container wall 130 'so that treatment fluid introduced into the chamber 140 flows into the chamber 160 via the overflow edge 188 when the valve 170 is closed. When the substrate support is raised from the position shown in Figure 7 to that shown in Figure 8 Position is moved, the float 180 follows the movement of the substrate carrier 2, due to the buoyancy of the float 180. As a result, the level of the treatment fluid in the chamber 140 is always kept at the level of the substrate located in the substrate carrier 2, since the float of every movement of the substrate carrier follows. This results in a simple and stepless height adjustment of the overflow edge 188 for the chamber 40 depending on the distance between the substrate 7 and the inner container wall 128. Although the floating body 180 is shown to have a substantially closed hollow chamber 184 as a buoyancy body, the floating body 180 can also have a different shape and be made from a solid material with good buoyancy, such as styrofoam.

The second exemplary embodiment of a height-adjustable overflow element 182, which is shown on the right in FIGS. 7 and 8, is described below. The overflow element 182 has a base body 192 with an outer circumference which is adapted to the inner circumference of the outer container wall 130 'and is guided through the wall 130' in a substantially vertically displaceable manner. The base body 192 has an upper section that tapers to an overflow edge 194. Below the tapered section, the overflow element 182 has a support flange 196 which extends essentially vertically radially inwards. The support flange 196 is angled 90 degrees downward at the radially inner end to form a pocket for receiving a spring 198, the function of which will be explained in more detail below. A spacer extends from the support flange 196 at a right angle 200 upwards, which, like the spacer 190, sets a predetermined distance between the height-adjustable overflow element 182, in particular the overflow edge 194 and the substrate holder 2.

The spring 198 is a compression spring and, as can be seen in FIGS. 7 and 8, it is arranged between a bottom of the chamber 140 and an underside of the support flange 196 and is suitably fastened to it.

In use, the spring 198 pushes the overflow element 182 upwards until the spacer 200 comes into contact with an underside of the substrate holder 2. As long as there is no substrate holder above the process container, the upward movement of the overflow element is limited by a stop, not shown. When the spacer 200 comes into contact with the underside of the substrate holder 2, the overflow edge 194 lies essentially at the same level as a substrate accommodated in the substrate holder 2. When the substrate holder 2 is moved from the position shown in FIG. 7 to the position shown in FIG. 8, the overflow element 182 follows the movement of the substrate carrier due to the spring preload, so that the height relationship between the substrate and the overflow edge 194 is maintained.

The operation of the device according to the exemplary embodiments in FIGS. 7 and 8 is essentially the same as in the exemplary embodiment in FIGS. 4 to 6. The substrate is first brought into the position shown in FIG. 7 and the flow of treatment fluid flows from below, see above that treatment fluid flows into chamber 140. The treatment fluid is discharged from the chamber 140 via the Valve 170 drained. The valve 170 is then closed so that the treatment fluid accumulates in the chamber 140. In the embodiment of a floating body as a height-adjustable overflow element, it floats until it comes into contact with the substrate carrier, as shown in FIG. With the spring-biased overflow element, contact with the substrate carrier is achieved from the start by the spring biased upwards. Subsequently, the substrate carrier 2 is raised in order to enlarge the gap between the substrate and the inner container wall 128. The height-adjustable overflow element 180 or 182 follows the movement of the substrate carrier, so that the respective overflow edge 188 or 194 lies at the height of the substrate received in the substrate carrier 2. In the exemplary embodiments shown in FIGS. 7 and 8, an essentially stepless adjustment of the overflow edges 188 and 194, which follows the position of the substrate carrier 2, is possible.

The device was described on the basis of preferred exemplary embodiments without being limited to the specific forms shown. For example, the process container 3 can be formed in one piece and the space 32 below the funnel element 30 could be omitted. The funnel element and / or the perforated plate 30 can also be omitted in certain applications. Furthermore, the device is not limited to the metal plating of wafers. It is also suitable for plating other substrates or for other treatment processes.

Claims

claims

1. Device (1) for treating substrates (7), in particular semiconductor wafers, with a process container (3) having a container wall (44) and a substrate holder (2) which is movably arranged above the process container (3) and which spaces the substrate Positioned above the container wall, characterized by an outwardly widening inner circumference of an edge of the container wall (44) facing the substrate.

2. Device (1) according to claim 1, characterized in that the substrate (7) with the substrate holder (2) can be positioned at different distances above the edge of the container wall (44).

3. Device (1) according to claim 2, characterized in that the edge of the container wall (44) in a position of the substrate (7) is directed to a contact area between the substrate holder and the substrate.

4. The device (1) according to claim 3, characterized in that the distance between the substrate (7) and the edge of the container wall (44) in one position is the smallest possible distance.

5. Device (1) according to one of the preceding claims, characterized in that the thickness of the container wall (44) tapers towards the edge.

6. The device (1) according to claim 5, characterized in that the taper is formed by contouring the outer circumference (58) of the container wall (44).

7. The device (1) according to claim 6, characterized in that the contouring of the outer circumference (58) of the container wall (44) is adapted to an inner circumferential shape of a carrier ring (6) of the substrate holder (2).

8. Device (1) according to one of the preceding claims, characterized by an anode arrangement (50) within the process container (3).

9. The device (1) according to claim 8, characterized in that the anode arrangement (50) is formed by a perforated plate.

10. The device (1) according to claim 8, characterized in that the anode arrangement (50) by a

Expanded mesh is formed.

11. The device (1) according to any one of the preceding claims, characterized by a contact arrangement on the substrate holder (2).

12. The device (1) according to claim 11, characterized in that a contact to the process container surface of the substrate (7) is electrically contactable via the contact arrangement.

13. The device (1) according to any one of the preceding claims, characterized by a to the substrate (7) widening funnel-shaped bottom of the process container (3).

14. The device (1) according to claim 13, characterized in that the funnel-shaped bottom is formed by an insert (30).

15. The device (1) according to claim 13, characterized in that the funnel-shaped bottom is formed in one piece with a vertical container wall (16).

16. The device (1) according to claim 13, characterized in that the funnel-shaped bottom forms part of the container wall.

17. Device (1) according to one of the preceding claims, characterized by at least one perforated plate (38) between a bottom of the process container (3) and the substrate (7) facing edge of the container wall (44) of the process container (7).

18. Device (1) according to one of the preceding claims, characterized by an overflow collar (60) surrounding the process container (3).

19. The device (1) according to claim 18, characterized by an upwardly open space between the container wall (44) of the process container (3) and the overflow collar (60).

20. The device (1) according to claim 18 or 19, characterized in that the overflow collar (60) higher than is the edge of the container wall (44) facing the substrate (60).

21. Device (1) according to one of claims 18 to 20, characterized by an outlet (64) in the overflow collar (60).

22. The device (1) according to any one of the preceding claims, characterized by a further process container (3) surrounding the process container (3).

23. Device (1) according to one of the preceding claims, characterized by its use as a metal plating device.

24. Process for treating substrates, in particular semiconductor wafers, with the following process steps:

- moving a substrate (7) by means of a substrate holder into a first position above and spaced apart from a container wall (44) of a process container (3);

- Guiding a treatment fluid through the process container onto a surface of the substrate (7) facing the process container, the treatment fluid passing over an outwardly widening inner peripheral surface of an edge of the container wall (44) of the process container (3) facing the substrate to an outer region of the Substrate (7) is directed.

25. The method according to claim 24, characterized by lifting the substrate (1) in a from the edge of the container bottom wall (44) of the process container (3) further apart second position.

26. The method according to any one of the preceding method claims, characterized by applying a voltage between an anode arrangement located in the process container (3) and the substrate (7).

27. The method according to claim 26, characterized by electrical contacting of the process container (3) facing surface of the substrate (7).

28. The method according to claim 26 or 27, characterized by changing the applied voltage depending on the position of the substrate (7).

29. The method according to any one of claims 26 to 28, characterized in that the applied voltage in the second position of the substrate (7) is higher than in the first position.

30. The method according to any one of the preceding method claims, characterized by homogenizing the flow directed onto the substrate (7) within the process container (3).

31. The method according to claim 30, characterized in that the homogenization takes place over a funnel-shaped bottom of the process container (3) and / or at least one perforated plate (38) arranged in the process container.

32. Method according to one of the preceding method claims, characterized by opening an outlet in an overflow collar (60) surrounding the edge of the process container when the substrate 4, 1) is in the first position.

33. Method according to one of the preceding method claims, characterized by closing an outlet in an overflow collar (60) giving the edge of the process container (3) when the substrate (7) is in the second position.

34. The method according to claim 33, characterized by damming treatment fluid within the overflow collar (60) until the treatment fluid reaches a height which is at least at the height of the substrate (7).

35. Device for treating substrates with a container fillable with treatment fluid, one

Overflow surrounding the container and a substrate holder for positioning a substrate above the container, characterized by a control device for controlling a treatment fluid level in the overflow as a function of the distance of the substrate holder from the container.

36. Apparatus according to claim 35, characterized in that the control unit has a controllable outlet valve in the overflow.

37. Apparatus according to claim 35 or 36, characterized by a further overflow arranged adjacent to the overflow.

38. Device according to one of claims 35 to 36, characterized by a height-adjustable overflow edge.

39. Apparatus according to claim 38, characterized by a floating body having the overflow edge.

40. Apparatus according to claim 38, characterized by a slide having the overflow edge.

41. Apparatus according to claim 40, characterized in that the slide is biased upwards by means of a spring.

42. Device according to one of claims 35 to 41, characterized by a spacer between the

Float or the slide and the substrate holder.

43. A method for treating substrates with a treatment fluid, in which a substrate with a substrate holder is held above a basin surrounded by an overflow and the flow of treatment fluid flows from below, characterized in that the level of the treatment fluid in the overflow is dependent on is controlled by the distance between the substrate holder and the basin.

44. The method according to claim 43, characterized in that the treatment fluid level is controlled via an outlet valve.

45. The method according to claim 43 or 44, characterized in that the treatment fluid level is controlled via a height-adjustable overflow edge.

46. The method according to claim 45, characterized in that the height of the overflow edge is controlled by the substrate holder.

47. The method according to claim 45 or 46, characterized in that an element having the overflow edge is biased towards the substrate holder.