JPH06286869A - Substrate holder - Google Patents

Abstract

PURPOSE:To provide a substrate holder enabling a substrate (wafer) with the clean surface to be efficiently obtained and lengthening the change cycle of cleaning liquid or the like. CONSTITUTION:A substrate holder 2 is provided with frame members 25, 25, 26, 26 laid two each in the upper and lower stages across leg parts 20, 20 so as to be able to hold a wafer 1 in the vertical attitude. The upper stage frame members 25, 25 support both side parts of the wafer 1, and the lower stage frame members 26, 26 support the obliquely lowerfer 1. Grooves 27, 28 for inserting the outer peripheral edge of the wafer 1 are formed at the frame members 25, 26. In order to remove water droplets accumulated between the grooves 27, 28 and the wafer 1, relief parts communicated with the grooves 27, 28 and opened facing downward or obliquely downward are formed at the bottom parts of the grooves 27, 28. The clean wafer can be thereby obtained, and the time required for drying can be shortened.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate holder, and more particularly to a wafer carrier used for holding a wafer in a semiconductor wafer cleaning process or etching process.

[0002]

2. Description of the Related Art In a semiconductor wafer manufacturing process, for example, the surface of a wafer is cleaned by removing contaminants such as abrasives, metal impurities, organic pollutants, particles, etc. after mirror finishing of the wafer. To this end, degreasing cleaning using an organic solvent and rinsing cleaning with water are performed. When such cleaning is performed by batch processing capable of cleaning a plurality of wafers at the same time, conventionally, one wafer 1 is placed in a groove 110 of a wafer carrier (holder) 100 as shown in FIGS. 6 and 7. The carrier 100 was immersed in a bath containing a cleaning liquid and the like. Also in the drying step after cleaning, the carrier 100 as well as the carrier 100 are installed in a drying device to remove and dry the water adhering to the wafer 1 by a method utilizing centrifugal force or the like. The wafer carrier 100 described above is also used when the wafer 1 is etched.

[0003]

However, the above-mentioned wafer carrier 100 is provided with the side plate 120 having a large number of grooves 110 into which the wafer 1 is inserted and the bottom plate 130 having a substantially ship-bottomed shape with the central portion opened. Since the wafer 1 is provided, when the wafer 1 is inserted into substantially all the grooves 110 of the carrier 100 and submerged in the cleaning liquid, the following problems occur. That is, since the inside and the outside of the wafer carrier 100 are separated by the side plate 120, the bottom plate 130, and the wafer 1, the cleaning liquid stays in the carrier 100 and is less likely to be replaced with the cleaning liquid on the outside, so that the cleaning effect is improved. It is said to decrease. In particular, when the cleaning process is repeatedly performed and the liquid becomes contaminated, the cleaning effect is remarkably reduced, and stains and the like may remain on the outer peripheral edge of the wafer 1. Further, since the groove 110 is provided so as to sandwich the outer peripheral edge of the wafer 1 from the side part of the wafer 1 to the obliquely lower part, the drainage of the carrier 100 when taking out the carrier 100 from the cleaning liquid is poor and the contaminants floating in the cleaning liquid are Carrier 10
There is also a problem that the cleaning liquid remains in the groove 0 of 0 or the cleaning liquid is mixed in the next rinse cleaning tank. further,
Due to poor drainage of water, there was a problem that it took a long time to dry. The same inconvenience occurred in the etching process.

The present invention has been made in order to solve the above-mentioned problems, and it is possible to efficiently obtain a substrate (wafer) having a clean surface by eliminating retention of a cleaning liquid and improving drainage. An object of the present invention is to provide a substrate holder capable of prolonging a cycle of exchanging a cleaning liquid or the like.

[0005]

In order to achieve the above object, a substrate holder according to the present invention comprises at least three rod-shaped frame members that can contact the outer peripheral edge of the lower half of the substrate to be processed. It is provided so as to extend in a direction orthogonal to the above, and a V-shaped groove for inserting the outer peripheral edge of the substrate is formed at a contact portion of each of the frame members with the substrate. Specifically, two rod-shaped frame members made of crystalline quartz, amorphous quartz, low-alkali tempered glass, fluororesin, polypropylene, polycarbonate, and other various synthetic resins are arranged in the same direction in two rows. The substrate to be processed is supported from below by a frame member in the lower stage, and both sides of the substrate are supported by the frame member in the upper stage to hold the substrate in a vertical posture. Then, a groove having, for example, a substantially V-shaped cross section for stabilizing the substrate is provided in each of the frame members. Further, the bottom of the groove is provided with a hole for letting a liquid such as a cleaning liquid which may be accumulated in the groove flow, that is, a concave escape portion.

[0006]

According to the above-mentioned means, the substrate holder has a structure in which the substrate is supported by three or four rod-shaped frame members, and a side plate for separating the inside and the outside of the substrate holder is provided. Since there is no bottom plate, even if the holder is fully loaded with the substrate and immersed in a bath containing cleaning liquid, the liquid does not stay in the holder and the liquid between the substrates is always retained. Since the liquid is exchanged with the liquid on the outer side, deterioration of the cleaning effect and the like is suppressed. In addition, since there is no side plate or bottom plate and the contact area between the holder and the substrate is much smaller than the contact area in the conventional wafer carrier, the drainage of the holder when pulled out of the liquid is good. At that time, the liquid accumulated in the gap between the groove and the substrate flows into the escape portion provided at the bottom of the groove, and the dripping from the holder is promoted. The carry-out of chemicals is suppressed as much as possible.

[0007]

EXAMPLES The features of the present invention are clarified by giving Examples and Comparative Examples in which the GaAs single crystal wafer to be the substrate is washed in the usual manufacturing process using the substrate holder according to the present invention. To The substrate holder 2 shown as an example in FIGS. 1 and 2 has a rod-shaped frame member 25, 25, 26, 26 made of, for example, amorphous quartz (fused quartz) between the leg portions 20, 20 provided at both ends thereof. 2 are provided above and below, for example, a circular wafer 1 (see FIG.
Then, one sheet is indicated by a chain double-dashed line. ) Can be held in a vertical position. The upper frame members 25, 25 support both side portions of the wafer 1, and the lower frame members 26, 26
Support an obliquely lower part of the wafer 1. Grooves 27 and 28 into which the outer peripheral edge of the wafer 1 is inserted are formed in the frame members 25 and 26 so as to have a substantially V-shaped cross-sectional shape as shown in FIG. To stand up. Further, for example, the leg portion 20 is formed by the rod-shaped frame members 21, 22, 23, and 24 so as to have a substantially square ring shape.

As a modification of the groove 27 (28) described above, as shown in FIG. 4 and FIG. 5, water drops and the like that may accumulate between the wafer 1 and the bottom of the groove 27 (28) are quickly removed. The recessed escape portion 29 may be formed. This escape part 2
9 communicates with the groove 27 (28) so that water droplets may flow therein, and the water droplets that have flowed into the frame member 25 (2
6) The opening faces downward or obliquely downward so as to drop from 6).

(Embodiment 1) As shown in FIGS. 2 and 3,
In the substrate holder 2 having no escape portion 29, G
Twenty-five wafers each having a diameter of 4 inches which were cut out from the aAs single crystal and subjected to polishing were set as one set and aligned in the mirror polishing direction, and three sets (75 sets in total) were subjected to batch processing. During this time,
The cleaning liquid was continuously used without replacement (hereinafter, the same applies to Example 2 and Comparative Example). Then, after the substrate holder 2 was dried, the surface condition of the wafer was observed. The number of wafers in which contamination was found is shown in Table 1. As is clear from the table, no contamination was found in all 75 wafers.

[Table 1]

(Embodiment 2) As shown in FIGS. 4 and 5,
Using the substrate holder 2 provided with the escape portion 29, as in the first embodiment, three sets of batch processing, each including 25 wafers having a diameter of 4 inches, were performed. As a result of observing the wafer surface, as shown in Table 1, no contamination was found on all 75 wafers.

(Comparative Example) Using the conventional wafer carrier 100 shown in FIG. 6, three sets of batch processes were carried out in the same manner as in Example 1 above. As shown in Table 1, no contamination was found on 25 wafers in the first batch, but 2 wafers were found on 25 wafers in the second batch, and 5 wafers were found on 25 wafers in the third batch. Was given. Of these 7 wafers, 3 wafers were found to have stains of opposite shapes on both sides of the outer periphery, and 5 wafers had irregular stain stains on their edges. Admitted. All the wafers that were soiled in a spot shape were mounted around the center of the wafer carrier 100. The wafer carrier 100 used was made of tetrafluoroethylene resin.

As described above, according to Examples 1 and 2, even if the cleaning process was repeatedly performed, the cleaning effect was hardly decreased and a clean wafer could be obtained.
Also, since the water was drained well, there was almost no need to take out the cleaning liquid, and it was not necessary to replenish or replace the chemical liquid. Furthermore, the time required for drying could be shortened.

The shape of the substrate holder 2 is not limited to that of the above-mentioned embodiment, and if the wafer can be held in an upright state, for example, the number of frame members 25 and 26 and their arrangement can be determined. Of course, the design may be changed to.
The material of the substrate holder 2 is not limited to amorphous quartz, but may be crystalline quartz, low alkali tempered glass, fluororesin, polypropylene, polycarbonate, various other synthetic resins, or a combination thereof. Further, although the substrate holder 2 is used for cleaning the GaAs single crystal wafer having a diameter of 4 inches in the above embodiment, it can also be used for etching. Further, it goes without saying that a wafer made of InP, Si or the like, or a thin plate other than the wafer can be used for cleaning the thin plate regardless of its shape and size.

[0014]

EFFECTS OF THE INVENTION By using the substrate holder according to the present invention, it is possible to prevent the liquid or the like from staying in the holder, so that it is possible to suppress the deterioration of the cleaning effect and the water drainage. Since it is extremely good, it is possible to prevent adhesion of stains and the like to the substrate due to the liquid accumulated in the groove of the holder, and to obtain a clean substrate. Also, because the water drains well
The amount of chemical solution taken out is reduced and the cycle of replenishment and replacement of cleaning solution, rinse solution, etc. can be lengthened, so that the economic effect is great and the time required for drying can be shortened, and wafers, etc. can be shortened. Manufacturing efficiency is improved.

[Brief description of drawings]

FIG. 1 is an overall perspective view showing an example of a substrate holder according to the present invention.

FIG. 2 is a vertical cross-sectional view showing a state where a wafer is stored in the substrate holder.

FIG. 3 is a cross-sectional view of essential parts showing a state where the outer peripheral edge of the wafer is housed in the groove of the substrate holder.

FIG. 4 is a vertical cross-sectional view showing a state in which a wafer is stored in a substrate holder having an escape portion in its groove.

FIG. 5 is a cross-sectional view of essential parts showing a state in which the outer peripheral edge of the wafer is housed in a groove having an escape portion.

FIG. 6 is an overall perspective view of a conventional wafer carrier.

FIG. 7 is a vertical cross-sectional view showing a state where a wafer is stored in the wafer carrier.

[Explanation of symbols]

 1 Wafer (Substrate) 2 Substrate Holder 25, 26 Frame Material 27, 28 Groove 29 Relief Part

Claims (3)

[Claims] 1. A holder which is used when a thin plate-like substrate is immersed in a liquid and which can be inserted and removed from above and which can hold the substrate in a vertical posture. At least three rod-shaped frame members that can contact the peripheral edge are provided so as to extend in a direction orthogonal to the substrate, and the outer peripheral edge of the substrate is inserted into the contact portion of each frame member with the substrate V
A substrate holder characterized in that a V-shaped groove is formed. 2. The bottom of the groove is provided with a recessed escape portion that allows liquid that may stay in the groove to communicate with the groove, and the escape portion is open facing downward. The substrate holder according to claim 1, wherein: 3. One or two selected from the group consisting of crystalline quartz, amorphous quartz, low alkali tempered glass, fluororesin, polypropylene, polycarbonate, and synthetic resin.
3. The material according to claim 1, wherein the material is made of one or more kinds of materials.
The substrate holder described.