JPS63155622A - Washing system for semiconductor substrate - Google Patents

Abstract

PURPOSE:To simplify the structure of a washing scrubber for the reverse side of a wafer and to operate the scrubber stably by a method wherein the peripheral part on the reverse side of the vacuum-sucked wafer is washed again and is dried by turning this substrate at high speed. CONSTITUTION:Arms 1b which support turning rollers 1a and set the rollers upright or tilt the rollers inward and outward are provided; the space between the rollers is made wider by tilting the arms toward the outside; a wafer 13 is set at this space. After that, the arms 1b are tilted toward the inside and the outside; two or more rollers 1a are brought into contact with the peripheral part of the wafer so as to hold the wafer; the surface and the reverse side of the wafer are washed. The following are provided: a spinning chuck 7 whose diameter is smaller than a spinning chuck 5 and which vacuum-sucks the central part in a small area on the reverse side of the wafer and is revolved at high speed; a brush which washes the area which is larger than the vacuum-sucked part at the peripheral part on the reverse side of the wafer at the spring chuck 5. The peripheral part on the reverse side of the wafer is washed again and is dried by turning the wafer at high speed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a single-wafer type semiconductor substrate cleaning apparatus used in a semiconductor device manufacturing process.

[Conventional technology]

Conventionally, single-wafer type semiconductor substrate cleaning equipment (hereinafter referred to as a scrubber) uses a scrubber that uses brush friction (hereinafter referred to as a brush scrubber), a scrubber that uses spraying of high-pressure cleaning liquid (hereinafter referred to as a jet scrubber), or a scrubber that uses a spray of high-pressure cleaning liquid (hereinafter referred to as a jet scrubber). ,
The mainstream was to clean the wafer surface using a scrubber that combined the two (hereinafter referred to as a combination scrubber).

However, in recent years, as the performance and density of hemihepatic elements have increased, higher cleanliness has been required, and the need for cleaning the backside of the wafer has also increased, and devices that can achieve this have also appeared.

As shown in FIG. 4, the scrubber that also cleans the back side of the wafer is equipped with a wafer chuck in which a plurality of rollers 10 each having a function of rotating on its own axis are attached to a spin shaft 12 via an arm 11 that can be raised and lowered inwardly and outwardly. The peripheral edges of the wafer 13 are mechanically held by the rollers 10 without contact between the front and back surfaces, and the wafers are cleaned by a brush or by spraying high-pressure cleaning liquid, and then the entire wafer chuck is rotated at high speed to dry the wafer.

[Problem that the invention seeks to solve]

The scrubber shown in Fig. 4 has a complex mechanism because its wafer chuck itself has many functions such as high-speed rotation function, arm opening/closing function, and roller rotation function. Since the wafer is held with enough force to withstand the wafer, there is a high risk of chipping at the wafer edge.

Furthermore, as the wafer size increases, the above-mentioned unstable factors become more prominent.

Therefore, conventional scrubbers that also clean the backside of wafers cannot be expected to operate stably mechanically or process-wise.

An object of the present invention is to provide a semiconductor substrate cleaning apparatus that performs wafer cleaning in a stable operating state.

[Means for solving problems]

The present invention provides an apparatus for cleaning the back surface or both front and back surfaces of a semiconductor substrate, and includes means for vacuum suctioning the peripheral edge of the back surface of a cleaned wafer, rotating the wafer at high speed, and drying mainly the center of the wafer; A semiconductor substrate cleaning apparatus characterized by having means for vacuum suctioning the central part of the back surface of a dried wafer, cleaning again the peripheral part of the back surface of the wafer vacuum suctioned in the previous stage, and means for drying the substrate by rotating it at high speed. be.

〔Example〕

Next, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic diagram of an embodiment of the present invention.

The scrubber of the present invention holds the outer periphery of a wafer 13 with a plurality of rotating rollers 1a, and includes a wafer cleaning means 1 for cleaning the back surface or front and back surfaces of the wafer, and vacuum suction for the periphery of the wafer back surface to move the wafer at high speed. A wafer center drying means 2 that rotates and mainly dries the center of the wafer, and a wafer back surface periphery drying means 2 that vacuum-chucks the dried wafer back-side center and re-cleans the wafer back-side periphery that was vacuum-adsorbed in the previous stage. It is composed of a cleaning means 3a, a drying means 3b for drying the wafer back surface by rotating the wafer at high speed, and a wafer transport mechanism 4 that connects each cleaning and drying means.

The wafer cleaning means 1 shown in FIG. 1, similar to the wafer chuck of the conventional scrubber for cleaning the backside of a wafer explained in FIG. By tilting the arm 1b outward to widen the roller interval, and setting the wafer 13 in that space, the arm 1b is tilted inward and outward to bring the plurality of rollers 1a into contact with the peripheral edge of the wafer 13. The wafer is held and the front and back surfaces of the wafer are cleaned.
It does not have a drying function by rotating the entire wafer chuck at high speed.

2(a) and 2(b) are schematic diagrams of the means 2 for drying the central part of the wafer shown in FIG. 1 by high-speed rotation;
A spin chuck 5 that rotates at high speed and is equipped with a vacuum suction port 5a for non-contact vacuum suction at several points on the periphery of the wafer back surface at the center of the back surface of the wafer as shown in FIG. , and an exhaust pipe 6a for exhausting the inside of the cup 6.

FIG. 3 is a schematic diagram of means 3a and 3b for re-cleaning the peripheral edge of the back surface of the wafer shown in FIG. 1 and drying it by high-speed rotation, and the means 3b is the spin chuck 6 shown in FIG.
It has a spin chuck 7 which has a smaller diameter and which vacuum-chucks the central part of the back surface of the wafer within a small range and rotates at high speed. - The old means 3a has a brush 8 that cleans a larger area than the vacuum suction part on the periphery of the back surface of the wafer of the spin chuck 6 shown in FIG. 2(b). Means 3a,
3b are both accommodated in a cup 9 equipped with an exhaust pipe 9a.

In addition, the means 2 for drying the central part of the wafer shown in FIG.
A mechanism for cleaning the wafer surface may be integrated into one or both of them.

In addition, by carrying out the present invention, there is a concern that the back surface of the wafer may be vacuum-adsorbed and the wafer chuck may come into contact with the wafer, causing dust to adhere to the back surface of the wafer. The main problem is the movement of attached dust, and the problem is solved by cleaning the backside of the wafer before vacuum suction with the wafer chuck.

〔Effect of the invention〕

As explained above, the present invention configures a cleaning device by separating the many functions of the wafer chuck itself, thereby simplifying the mechanism and providing a wafer backside cleaning scrubber that operates stably. It has the following.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram showing an embodiment of the present invention, Fig. 2(a)
3 is a block diagram showing a means for drying the central part of a wafer by rotation in an embodiment of the present invention, (b) is a plan view of a spin chuck, and FIG. FIG. 4 is a schematic diagram showing means for drying by rotation. FIG. 4 is a schematic diagram showing a wafer chuck of a conventional scrubber that also cleans the back side of a wafer.

Claims (1)

[Claims] (1) In an apparatus for cleaning the back side or both front and back sides of a semiconductor substrate, a means for vacuum suctioning the peripheral edge of the back side of a cleaned wafer and drying the wafer mainly at the center by rotating the wafer at high speed; A semiconductor substrate cleaning apparatus characterized by having means for vacuum suctioning the central part of the dried wafer backside, cleaning again the wafer backside peripheral part vacuum suctioned in the previous stage, and means for drying the substrate by rotating it at high speed. .