JPH07283189A - Vapor cleaner - Google Patents

Abstract

PURPOSE:To efficiently heat a washing liq. in the vapor cleaning, without causing uneven temp. distribution even when this uses a mixed liq. CONSTITUTION:A semiconductor wafer 2 is held with a carrier 4 in an upper space of a casing 1, storage tanks 3a and 3b are disposed in the bottom of the casing 1, washing liqs. S1 and S2 which are components of a washing liq. are separately stored in the tanks 3a and 3b and heaters 5a and 5b are disposed in the tanks 3a and 3b, respectively. The liqs. Sl and S2 are respectively heated to produce vapors by which a semiconductor wafer 2 is cleaned. This makes it practicable to do an adequate vapor production control for each chemical liq., prevent uneven temp. distribution in the mixed liq. and ensure a high- cleanness vapor cleaning.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steam cleaning apparatus for cleaning the surface of an object to be cleaned with steam.

[0002]

2. Description of the Related Art Conventionally, various impurities are attached to the surface of a semiconductor substrate such as a silicon wafer or a mask during the process of processing, and a vapor cleaning method is known as a cleaning method for removing them. Kaihei No. 2-177327 / JP-A-5
-41139 gazette). In the heating structure for generating steam in such an apparatus, a heater is attached to the outside of the cleaning liquid storage tank. Further, JP-A-2-185031 discloses that steam once generated is reheated before being sprayed by a steam nozzle.

However, when a mixed liquid containing water (HCL, HF, H ₂ O _2, etc.) is used as the cleaning liquid, temperature unevenness due to convection easily occurs in the aqueous solution, and the composition of the steam may change over time. There is. Further, when the steam generated by heating once is reheated, the reheated portion has to be kept at a high temperature, and it is easy to contain fine particle dust or metal in the steam, which may contaminate the wafer.

[0004]

In view of the problems of the prior art as described above, the main object of the present invention is to enable efficient heating without causing temperature unevenness even when a mixed solution is used as the cleaning solution. It is to provide a steam cleaning device.

[0005]

According to the present invention, such an object is to provide a steam generating portion for generating a steam of a cleaning liquid for cleaning the object held in the upper space of the casing with the casing. In the vapor cleaning device having a lower portion, the vapor generating unit, a plurality of storage tanks provided independently of each other to separately store a plurality of types of chemical liquids constituting the cleaning liquid, and each of the storage tanks. This is achieved by providing a vapor cleaning apparatus characterized by comprising heating means provided for each of the storage tanks so as to individually vaporize each of the chemical liquids.

[0006]

With this configuration, when the cleaning liquid is composed of a mixed liquid, it can be heated for each individual chemical liquid, and when the cleaning liquid composed of the mixed liquid is heated at one time, unevenness occurs for each individual chemical liquid. Can be prevented.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will now be described in detail with reference to the accompanying drawings.

FIG. 1 is a schematic vertical sectional view showing a steam cleaning apparatus to which the present invention is applied. In this apparatus, as shown in the figure, a semiconductor substrate 2 as an object to be cleaned is held in the upper space of a container-shaped casing 1 whose entire surface is covered, and a plurality of (two in the figure) are provided on the bottom surface of the casing 1. Storage tank 3a
3b is provided as a recess. The semiconductor substrate 2
For example, 25 sheets are arranged side by side in the front-back direction on the paper surface of the figure, and are supported by a carrier 4 formed in a long cage shape with a frame structure.

In each of the storage tanks 3a and 3b, the chemical liquids S1 and S2 that form a cleaning liquid for cleaning the semiconductor substrate 2 with steam are used.
Are stored respectively. The cleaning liquid may be, for example, a mixed liquid containing water (HCL, HF, H ₂ O ₂ or the like), and is stored by being divided for each aqueous solution or each mixed liquid unit. In the embodiment, an example in which two storage tanks 3a and 3b are provided is shown. However, there is no problem in providing three or more storage tanks, and the number of storage tanks corresponding to the type of each chemical solution of the mixed solution is provided. Is also good.

Further, the storage tanks 3a and 3b are provided with heaters 5a and 5b as heating means. Heater 5
a and 5b are storage tanks 3a and 3b, as shown in FIG.
The heating wires are received in plate-shaped glass tubes or Teflon plates which are erected on the bottom surface of the plate and are arranged in parallel with each other with a space therebetween. These heating wires are collected for each storage tank 3a and 3b and electrically connected to an electric heating control device (not shown). When a glass tube is used, it is preferable that the material is made of quartz glass and the outer surface of the glass tube is treated with Teflon to improve chemical resistance. The heaters 5a and 5b may be formed in a wall shape extending in the front and back directions on the paper surface of the drawing.
In that case, a through hole may be provided at the bottom of each heater 5 so that the cleaning liquid S can easily flow between the heaters 5a and 5b.

In the vapor cleaning apparatus thus constructed, when the semiconductor substrate 2 is vapor-cleaned, the chemicals S1 and S2 in the storage tanks 3a and 3b are heated by the heater 5, The vapor of each chemical solution is generated as shown by the dashed arrow in the figure. The vapors of the chemical liquids S1 and S2 are mixed with each other as they rise in the casing 1, and reach the semiconductor substrate 2 as vapors of the cleaning liquid having the above-described composition. By using the mixed solution having the above composition, metal and particles (adhered particles) can be suitably removed. Further, the amount of metal contained in the vapor is one digit or more smaller than that in the liquid, and the cleaning can be performed with an extremely clean liquid.

Further, in order to prevent the mist from scattering, the temperature is set to 95 ° C. so that the cleaning liquids S1 and S2 are not boiled.
It controls below. The above control can be performed by disposing a temperature sensor in an appropriate place in each of the storage tanks 3a and 3b, and the evaporation amount can be controlled by further changing the temperature. Also, by controlling the temperature for each chemical,
Optimal vapor generation can be performed for each chemical liquid, and the amount of each chemical liquid can be minimized.

[0013]

As described above, according to the present invention, a plurality of storage tanks independent from each other are provided, and the cleaning liquid for steam cleaning is divided into chemical liquids having different compositions and stored in the respective storage tanks. By heating and evaporating by the heating means provided in, it is possible to perform appropriate evaporation control according to each chemical liquid, and to perform steam cleaning without causing uneven cleaning when the cleaning liquid consisting of mixed chemical liquid is partially heated. Highly clean cleaning can be efficiently performed.

[Brief description of drawings]

FIG. 1 is a schematic vertical sectional view showing a steam cleaning apparatus to which the present invention is applied.

FIG. 2 is a partially enlarged sectional view of a cleaning liquid storage tank of the steam cleaning device.

[Explanation of symbols]

 1 Casing 2 Semiconductor Substrate 3a / 3b Storage Tank 4 Carrier 5a / 5b Heater

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Kenichi Uemura, Komitsu-shi, Shimada 3434, Shin-Nippon Steel Co., Ltd.Inside of Komatsu Works (72) Inventor, Yoshihiro Mori, Koichi-shi, Shimada 3434, Nippon Steel Stock Association Inside the Shoko Ironworks

Claims (1)

[Claims] 1. A steam cleaning apparatus having a steam generator for generating steam of a cleaning liquid for cleaning the object to be cleaned held in an upper space of the casing in a lower portion of the casing, wherein the steam generator is , A plurality of storage tanks provided independently of each other to separately store a plurality of types of chemical liquids constituting the cleaning liquid, and provided for each storage tank to individually vaporize the chemical liquids of the storage tanks And a heating means provided therein.