JPH11284051A - Board carrying tray - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce variation and yield of an integrated circuit product by transmitting axially driving movement alone out of rotary movement and axially driving movement which are carried out by a board-carrying tray body to a board holding part whereto a board is attached when a board is mounted on a board holder. SOLUTION: A pin 27 of a board-carrying tray body 25 is thrusted while it is subjected to rotary movement along a screw-like groove 36 of a board holder 34 at the time when a board 21 is mounted on the board holder 34, and a D-surface (a rear of a film formation surface) of the board 21 is brought into contact with an E-surface of the board holder 34. The board carrying tray body 25 is rotated successively axially while being pushed against reaction of a spring 32 and pressing force of the board carrying tray 25 is transmitted from a bearing holder 30 to a bearing 31 through the spring 32 by a guide rod 29. Thereby, dispersion and yield of an integrated circuit product can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate carrying tray used for carrying a substrate into a vacuum processing chamber and mounting the substrate on a substrate holder in an apparatus for forming or etching a substrate surface in a vacuum.

[0002]

2. Description of the Related Art In order to manufacture various semiconductor integrated circuits such as memories and logics on a substrate, a process of forming a thin film on the substrate and etching the formed thin film along a certain pattern is required. Often. As a method for this etching, it is common practice today to use plasma generated in a vacuum vessel. However, in this plasma etching, electrons and ions in the plasma enter the substrate and are converted into thermal energy on the substrate, or the substrate itself is irradiated by radiant heat incident from the plasma itself, the facing electrode, and the wall surface of the vacuum vessel. There is a problem that the temperature rises. Further, as a heat source, reaction heat due to a chemical reaction may not be ignored in some cases.

[0003] If the temperature of the substrate becomes higher than necessary, various problems occur. One of them is, for example, a side etching phenomenon. The side etching phenomenon is a phenomenon in which, when a groove is dug into a thin film by etching, a wall surface orthogonal to the depth direction of the groove is etched more than a predetermined pattern shape. This is because the etching action is composed of the effect of the kinetic energy of the plasma particles in the processing chamber and the effect of the chemical reaction. Etching)
However, since the etching shape due to the chemical reaction is a chemical reaction, there is a fundamental cause of being basically isotropic (isotropic etching).

That is, even when the temperature of the substrate becomes high,
The etching action based on the kinetic energy hardly affects the etching shape and the etching rate. In particular, it can be said that there is no effect in principle in terms of directionality. However, the rate of a chemical reaction is greatly affected by the temperature. That is, as the temperature increases, the reaction rate increases. As a result, when the temperature of the substrate is increased, in plasma etching, the ratio of participation by the chemical reaction generally increases, and the ratio of isotropic etching increases. As a result, side etching is more likely to occur. Can be explained.

[0005] As described above, if the substrate temperature becomes unnecessarily high, the pattern shape of the thin film deteriorates, so that it is necessary to cool the substrate and control the temperature.

The optimum substrate temperature differs depending on the type of film to be formed and the shape of the groove to be processed. For example, when helicon or ECR is used as an ion source and GaAs is etched with chlorine gas, the temperature is controlled to 10 ° C. or less.

[0007] Conversely, depending on the material, the desired etching may not be possible unless heated positively.
For example, in the case where Pt or InP is etched with chlorine, unless the substrate is heated, chloride deposits on the substrate surface to hinder the etching. In this case, the etching must be performed by heating the substrate to 100 ° C. to 150 ° C. or more so as to prevent chloride from being deposited.

Although the above description has been made with respect to the etching as an example, the necessity of controlling the temperature of the substrate during the plasma processing is not limited to the etching but also occurs in a thin film forming process such as sputtering or CVD. In order to control the temperature of the substrate, it is necessary to control the temperature of the substrate holder on which the substrate is placed during plasma processing by some method, so as to control the temperature of the substrate placed in close contact with it. Has been done conventionally.

A specific example for this will be described below with reference to the drawings. FIGS. 5A and 5B show a manual operation device or a switch operation device mainly used for research, in which the substrate size is about φ1 inch to φ3 inch, and the ultimate vacuum degree is 10 ⁻⁵ P.
This is a relatively small etching apparatus which has been used for research mainly for compound semiconductors, such as a or smaller. In such an apparatus, in order to avoid as much as possible the adverse effects of dust particles floating in the etching chamber, as shown in FIG.
Conventionally, a method has been adopted in which the substrate is transported from the outside into the processing chamber by setting the substrate vertically (with the substrate surface vertical). The illustration of the processing chamber is omitted.

FIG. 5A is a cross-sectional view of the substrate 2 attached to the transfer jig 1 before being mounted on the substrate holder 3 for plasma processing, and FIG. It is sectional drawing. FIG. 4 is an external perspective view showing the disassembled state of the configuration shown in FIGS. 5A and 5B.

The substrate transport tray 4 has a substantially cylindrical shape, and has a disc-shaped lid 5 on one side of the cylinder, and a space outside the cylindrical portion of the substrate transport tray 4. Three pins 6 are implanted. The substrate 2 is fixed to the outer surface (A surface) of the lid 5 of the substrate transport tray 4 by a leaf spring 7. The substrate may be attached to the substrate transport tray 4 by indium or the like.

To mount the substrate transfer tray 4 on which the substrate 2 is fixed to the substrate holder 3, first, the substrate transfer tray 4
The pin 6 is fitted into the L-shaped groove 9 cut into the transfer jig 1 and fixed to the transfer jig 1. This result is shown
Fig. 5b is a left view of Fig. 5a. In the state on the left side of FIG. 5A, the substrate 2 is carried into the vacuum processing chamber, and the next step is to transfer the substrate 2 fixed to the substrate transport tray 4 from the transport jig 1 side to the substrate holder 3 side. Then, the pins 6 of the substrate transport tray 4 are fed from the L-shaped grooves 9 of the transport jig 1 to the screw grooves 8 of the substrate holder 3. For this purpose, the conveying jig 1 is rotated rightward (in the direction of the arrow R) while pressing the pins 6 against the entrances of the screw grooves 8. When the pins 6 are sent to the end point of the groove 8 and the transport jig 1 no longer rotates, the transport jig 1 is pulled in a direction opposite to the transport direction (X direction in FIG. Substrate mounting is completed, after that, pull out the transfer jig from the processing chamber, close the entrance of the processing chamber,
After evacuation, the surface of the substrate is subjected to processing such as etching with a predetermined plasma.

The dimensions of the groove 8 are determined by the size of the substrate transport tray 4.
(The back side of the A side) and the E side of the substrate holder 3 are determined to be in close contact with each other. The pin holding spring 10 is used to fix the movement of the pin 6 so that the substrate carrying tray 4 is rotated by vibration or the like and the adhesion between the surface B and the surface E is not impaired. In addition, B of the substrate transport tray 4
The surface and the surface A for tightly fixing the substrate 2 are smooth-finished to increase the heat transfer efficiency, similarly to the surface E of the substrate holder 3.

The substrate holder 3 has a built-in temperature control device including a heater and a refrigerant circuit (not shown). By transmitting the heat of the substrate holder 3 whose temperature is controlled to the substrate 2, the temperature of the substrate 2 in close contact with the substrate 2 can be controlled. Then, in order to further increase the heat transfer efficiency, a gas such as He is blown out from the E surface of the substrate holder 3 so that the He gas is interposed on the contact surface of the substrate transfer tray 4 with the B surface. Increasing the heat transfer efficiency has also been performed.

[0015]

However, in the above-mentioned conventional apparatus, the substrate transfer tray 4 is rotated while the surface B of the substrate transfer tray 4 is brought into close contact with the surface E of the substrate holder 3, so that the substrate transfer tray 4 is repeatedly attached and detached. In addition, there is a problem that the contact surfaces of the substrates gradually become rough and the adhesion is deteriorated, and the efficiency of heating (or cooling) the substrate is reduced.

In order to keep the substrate temperature constant even when the heat transfer efficiency is reduced, in the case of substrate heating,
It was necessary to increase the heater temperature by supplying more electric power, or to lower the coolant temperature in the case of cooling the substrate. When He gas is also used, the temperature can be compensated by flowing more He gas. In this case, the gas filling the gap between the E surface and the B surface is in the vacuum vessel. And the pressure inside the vacuum vessel rises, causing a new problem.

[0017] These various problems also cause a temperature difference between the processing substrates, so that the reproducibility of etching between the substrates cannot be obtained, and as a result, there is a serious problem such as a variation between products and a reduction in yield. It also caused trouble. Further, depending on the product, the number of dusts in the vacuum container also has a great effect on the product yield. Particularly, in recent years, the density of semiconductor integrated circuits has been increased, and countermeasures against dust in a vacuum vessel have often been one of the most important issues. In this respect, in the conventional apparatus, there is also a problem that dust is easily generated from the sliding portion between the surface B of the substrate transport tray 4 and the surface E of the substrate holder 3.
SUMMARY OF THE INVENTION An object of the present invention is to provide an improved substrate transfer tray to solve the above-mentioned problem.

[0018]

A substrate transport tray according to the present invention is configured as follows to achieve the above object.

First substrate transfer tray (corresponding to claim 1)
When the substrate placed on the substrate transport tray and carried into the vacuum processing chamber by the transport jig is mounted on the substrate holder from the transport jig together with the substrate transport tray,
The protrusion provided on the outer side of the substantially cylindrical substrate transfer tray main body constituting the substrate transfer tray is engaged with a groove provided on the substrate holder, and is rotated along the groove to provide a screw effect. In a substrate transfer tray of a system for tightening and securing thermal contact between the substrate and the substrate holder, when the substrate is mounted on the substrate holder, the rotational movement performed by the substrate transfer tray body and the axial propulsion Of the exercise,
Only the axial propulsion motion is transmitted to the substrate holder on which the substrate is mounted.

When the substrate transport tray is used, when the substrate is mounted on the substrate holder, the substrate retainer on which the substrate is mounted does not rotate even if the substrate transport tray body rotates.
Roughness of the contact surface due to mounting on the substrate holder can be prevented.

Second substrate transfer tray (corresponding to claim 2)
In the first configuration, the tray body has a ring-shaped flange on one inner end surface of the cylinder, and has a groove along the inner periphery near the other end surface. A stop ring is fitted into the ring body, and between the ring-shaped collar portion of the tray body and the stop ring, the substrate is mounted with the center axis of the substrate and the center axis of the tray body aligned with each other, The substrate retainer held movably in the direction perpendicular to the substrate surface and a bearing holder movably held in the central axis direction of the tray body were mounted to receive an axial force. A bearing and a spring are provided. With the spring, the bearing is in rolling contact with the substrate holder or the ring-shaped flange portion, and the back surface of the substrate is mounted on the substrate attached to the substrate holder. It was as being constantly urged toward the mounting surface direction of the holder.

Third substrate transport tray (corresponding to claim 3)
In the first configuration, the tray body has a ring-shaped flange on one inner end surface of the cylinder, and has a groove along the inner periphery near the other end surface. The stop ring is fitted in, between the ring-shaped flange portion and the stop ring of the tray body, the substrate is mounted by aligning the center axis of the substrate and the center axis of the tray body,
A substrate retainer movably held in the direction perpendicular to the substrate surface, a sliding member installed to receive an axial force, and a spring, wherein the sliding member is provided by the spring; Alternatively, the substrate attached to the substrate retainer is constantly urged toward the mounting surface of the substrate holder while the sliding contact is made with the ring-shaped flange.

[0023]

1a and 1b show a cross section of an embodiment of the present invention. FIG. 1A is a cross-sectional view before mounting the substrate transport tray on the substrate holder, and FIG. 1B is a cross-sectional view during mounting.

The substrate holder 20 has a substantially cylindrical shape, and its inner diameter is slightly larger than the diameter of the substrate 21. On one end surface of the cylinder, there is provided a substrate mounting flange 22 facing the inside of the cylinder. A groove is cut in the inner periphery of the cylinder inside the flange. The substrate retaining ring 23 is configured to be accommodated in this groove. The retaining ring 23 is a leaf spring in which a circular plate is cut out concentrically at the center, a part of the remaining ring portion is cut out, and the final shape is substantially C-shaped. By pressing the outer circumference to bring the notched portion of C closer, the diameter of the outer circumference circle is reduced, and the diameter is expanded to the original diameter by releasing the force.

The substrate 21 is mounted on the substrate retainer 20 within the cylinder of the substrate retainer 20 by using a substrate mounting flange 22 and a substrate retaining ring 23. At the end opposite to the end provided with the substrate mounting flange portion 22 of the substrate holding member 20,
A bearing receiving flange 24 is provided toward the outside of the cylinder.

The substrate carrying tray main body 25 is substantially cylindrical. One end of the tube has a lid. This lid is substantially hollow at the center, and thus forms an inward flange (spring fixing flange 26). Three pins 27 are implanted radially around the outer periphery of the cylinder. Near the other end of the cylinder, a groove is cut along the inner circumference of the cylinder. A stop ring 28 having the same function as the substrate retaining ring 23 is fitted in this groove. The inner diameter of the cylinder is slightly larger than the outer diameter of the bearing receiving flange 24 of the substrate holder 20.

The guide rod 29 is mounted on the substrate carrying tray body 25.
Are fixed from the spring fixing flange 26 toward the stop ring 28 in parallel with the central axis of the substrate carrying tray main body 25.

The bearing retainer 30 has a substantially cylindrical shape, and has a flange 30a facing inward at one end. A plurality (three or more) of bearings 31 are provided inside the cylindrical portion, with their rotation center axes directed in the radial direction of the cylinder. The outer diameter of the bearing holder 30 is slightly smaller than the inner diameter of the substrate carrying tray main body 25. The inner diameter of the flange 30a is 20
Slightly larger than the outer diameter of the tube.

The flange 30a of the bearing retainer 30 has
A small hole into which the guide rod 29 is slidably fitted is clear. 32 is a compression spring.

To assemble the substrate carrying tray, a spring fixing flange 26 is provided in the cylinder of the substrate carrying tray main body 25.
The compression spring 32 is inserted from the opposite side, and then the bearing holder 30 with the bearing 31 is placed.
Then, the substrate holder 20 is placed in a state where the bearing 31 and the bearing receiving flange 24 are in contact with each other. Substrate holder 2
0, compression spring 32 through bearing retainer 30
While pressing, the stop ring 28 is inserted into the groove and fixed. At this time, the guide rod 29 is
Is inserted into the small hole. A substrate 21 is fixed to the substrate retainer 20 using a substrate retaining ring 23.

The substrate holder 20 is pushed by the compression spring 32 in a direction in which the substrate holder 20 is ejected from the substrate transport tray main body 25. The flange 24 of the substrate holder 20 is positioned near the other end of the substrate transport tray main body 25. The movement is stopped by the stop ring 28 which is fitted, and
Is pressed against the stop ring 28 via a bearing 31 by a compression spring 32.

In order to load the substrate transfer tray on which the substrate 21 is mounted into the processing chamber, first, the transfer jig 3 is used.
3 and its fixing method are the same as those already described as a conventional example. That is, first, the pins 27 implanted in the substrate carrying tray main body 25 are fitted into the L-shaped grooves 35 cut into the carrying jig 33. This state is shown on the left side of FIG. 1a. Transport jig 3 in this state
3 is carried into the substrate holder 34 in the processing chamber.

The form and structure of the substrate holder 34 are the same as those of the substrate holder 3 described in the prior art, except that the portion for mounting the substrate is small.

The substrate transfer tray assembly on the transfer jig 33 is
In order to transfer to the substrate holder 34, the pin 27 is rotated while the transport jig 33 is rotated to the right (the direction indicated by the arrow in FIG. R).
It is fed from the L-shaped groove 35 of the transfer jig 33 to the threaded groove 36 of the substrate holder 34. This state is shown in FIG. 1b. Pin 2
7 is fed to the end of the threaded groove 36 of the substrate holder 34, and when the transport jig 33 no longer rotates in the R direction, the transport jig 33 is pulled away in the X direction to transfer the substrate 21 to the substrate holder 34. Installation is complete.

By the way, the shape and dimensions of the thread groove 36 are determined so that the D surface of the substrate 21 and the E surface of the substrate holder 34 come into close contact with each other via the pressing force of the compression spring.
Although not shown in FIGS. 1A and 1B, a pin holding spring similar to the pin holding spring 10 of FIG. 4 described in the conventional example is provided, and the substrate carrying tray main body 25 rotates due to vibration or the like. The loosening prevents the adhesion from being impaired.

The surface E of the substrate holder 34 has a smooth finish. The back surface (D surface) of the substrate 21 is originally smooth-finished. Then, the substrate holder 34
Has a built-in temperature control device consisting of a heater and a refrigerant circuit, and the E side is constantly temperature-controlled. With the heat of the temperature-controlled substrate holder 34, it is possible to control the temperature of the substrate 21 in close contact with it. I can do it. In order to further increase the heat transfer efficiency, the substrate holder 3
It is also possible to blow out a gas such as He from the E surface of No. 4 to increase the heat transfer efficiency through the gas interposed between the E surface and the D surface of the substrate as in the related art.

In the present embodiment, the substrate transport tray having the above configuration is used.
7 is pressed while rotating along the threaded groove 36 of the substrate holder 34, so that the D surface (the surface on the back side of the film formation surface) of the substrate 21 first contacts the E surface of the substrate holder 34.
Further, when the substrate transport tray main body 25 is continuously rotated in the R direction while being pressed against the reaction force of the spring 32, the pressing force of the substrate transport tray main body 25 is
Further, the rotational force is controlled by the guide rod 29 by the bearing holder 30.
To the bearing 31. However, at this time, the substrate 21 attached to the substrate retainer 20 does not rotate due to the frictional force between the D surface and the E surface of the substrate holder 34, and does not rotate. Only the compression spring 31 and the compression spring 32 rotate together with the substrate transport tray main body 25. Therefore, the sliding phenomenon between the thermal contact surfaces, which is a problem in the conventional device, does not occur.

In FIG. 1, a description has been given of an example in which a radial bearing is used as a member for receiving an axial load, but a thrust bearing can of course be used.

In the above description, the bearing 3
The flange 24 of the board holder 20 was used as a surface to which 1 contacts, but as shown in FIG.
The flange 26 of the tray body 25 can also be used.

In all of the embodiments described above, the term "compression spring" has been used. However, this concept is not limited to compression coil springs, but also includes disc springs and elastic materials such as rubber. Can be included.

In addition, instead of the rotating bearing (bearing) described so far in the embodiment, a sliding member having a small friction coefficient and a small amount of dust is selected, and a surface contact is made.
It is of course possible to receive a thrust force. FIG. 3 shows a case where a ring-shaped sliding body 37 is used and a disc spring 38 is used as a compression spring.

The positions of the stop ring 28 and the spring fixing flange 26 provided on the substrate carrying tray main body 25 described above with reference to the drawings can of course be interchanged.

[0043]

By using the substrate transfer tray of the present invention, the substrate is transferred to the substrate holder at the contact surface for transferring heat to the substrate, that is, the contact surface between the D surface of the substrate and the E surface of the substrate holder. No sliding phenomenon occurs when mounting. For this reason, even if desorption is repeated, the occurrence of abrasion and roughening of the contact surface where heat transfer is performed is suppressed, so that the contact area for heat transfer does not change. Further, the contact pressure between the substrate and the substrate holder is kept constant by the constant reaction force of the elastic body. Together these effects stabilize the heat transfer efficiency between the substrate holder and the substrate. Therefore, the temperature control performance of the substrate is stabilized, and finally, an integrated circuit product having a good film-forming shape and a good etching shape can be obtained, and production with good reproducibility and improved yield can be realized. In addition, by using a rolling bearing such as a bearing, it is possible to further suppress dust generation in the vacuum vessel and to improve the yield of products.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a first embodiment of the present invention and showing a state in which a substrate is fixed to a transfer jig.

FIG. 2 is a cross-sectional view illustrating a state in which a substrate is transferred from a transfer jig to a substrate holder according to the first embodiment of the present invention.

FIG. 3 is a cross-sectional view showing a second embodiment of the present invention and showing a state in which a substrate is fixed to a transfer jig.

FIG. 4 is a cross-sectional view showing a third embodiment of the present invention and showing a state in which a substrate is fixed to a transfer jig.

FIG. 5 is an external perspective view of a conventional substrate transport tray in an exploded state.

FIG. 6 is a cross-sectional view illustrating a state in which a substrate is fixed to a transfer jig in a conventional substrate transfer tray.

FIG. 7 is a cross-sectional view showing a state in which a substrate is transferred from a transfer jig to a substrate holder in a conventional substrate transfer tray.

[Explanation of symbols]

 1: transport jig 2: substrate 3: substrate holder 4: substrate transport tray 5: lid 6: pin 7: leaf spring 8: screw groove 9: L-shaped groove 10: pin retaining spring 20: substrate retaining 21: substrate 22: Substrate mounting flange 23: Substrate retaining ring 24: Bearing receiving flange 25: Substrate carrying tray main body 26: Spring fixing flange 27: Pin 28: Stop ring 29: Guide rod 30: Bearing retainer 31: Bearing 32: Compression spring 33: Transport jig 34: Substrate holder 35: L-shaped groove 36: Screw-shaped groove 37: Ring-shaped sliding body 38: Belleville spring

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[Procedure amendment]

[Submission date] August 19, 1998

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Brief description of drawings

[Correction method] Change

[Correction contents]

[Brief description of the drawings]

FIG. 1a shows the first embodiment of the present invention and is a cross-sectional view before a substrate carrying tray is mounted on a substrate holder.

FIG. 1b shows the first embodiment of the present invention and is a cross-sectional view showing a state where a substrate carrying tray is being mounted on a substrate holder.

FIG. 2 is a cross-sectional view showing a second embodiment of the present invention and showing a state in which a substrate is fixed to a transfer jig.

FIG. 3 is a cross-sectional view illustrating a state where a substrate is fixed to a transfer jig according to a third embodiment of the present invention.

FIG. 4 is an external perspective view of a conventional substrate carrying tray in an exploded state.

FIG. 5a is a cross-sectional view showing a conventional substrate transport tray before mounting a substrate mounted on a substrate transporter and transporting the substrate to a substrate holder for plasma processing.

FIG. 5b is a cross-sectional view showing a conventional substrate transport tray, which is being mounted on a substrate holder for performing a plasma process on a substrate that has been transported attached to a substrate transport tool.

[Description of Signs] 1: Transport jig 2: Substrate 3: Substrate holder 4: Substrate transport tray 5: Lid 6: Pin 7: Leaf spring 8: Thread groove 9: L-shaped groove 10: Pin holding spring 20: Substrate retainer 21: Substrate 22: Substrate mounting flange 23: Substrate retaining ring 24: Bearing receiving flange 25: Substrate transport tray body 26: Spring fixing flange 27: Pin 28: Stop ring 29: Guide rod 30: Bearing retainer 31: Bearing 32: Compression spring 33: Transport jig 34: Substrate holder 35: L-shaped groove 36: Screw-shaped groove 37: Ring-shaped sliding body 38: Belleville spring

Claims (3)

[Claims] When a substrate placed on a substrate transfer tray and carried into a vacuum processing chamber by a transfer jig is mounted on a substrate holder from the transfer jig together with the substrate transfer tray, the substrate transfer is performed. By engaging a protrusion provided on the outside of the substantially cylindrical substrate carrying tray main body constituting the tray with a groove provided in the substrate holder, rotating along the groove, and tightening up with a screw effect. A substrate transport tray of a type for ensuring contact between the substrate and the substrate holder, wherein, when the substrate is mounted on the substrate holder, the rotational motion performed by the substrate transport tray main body and the axial propulsion motion; A substrate transport tray for transmitting only an axial propulsion motion to a substrate holder on which the substrate is mounted. 2. The tray body has a ring-shaped flange on one inner end face of the cylinder and a groove along the inner circumference near the other end face, and a stop ring is formed in this groove. The substrate is mounted so that the center axis of the substrate and the center axis of the tray body are aligned with each other between the ring-shaped flange portion of the tray body and the stop ring, and the substrate is mounted in a direction perpendicular to the substrate surface. The substrate holder held movably, a bearing attached to a bearing holder movably held in the central axis direction of the tray body, and a bearing installed to receive an axial force, and a spring. The bearing is provided by the spring,
Or the ring-shaped flange portion, while being in rolling contact with the ring-shaped flange portion, so that the substrate attached to the substrate retainer is constantly urged toward the mounting surface direction of the substrate holder on the back surface of the substrate. Substrate transfer tray. 3. The tray body has a ring-shaped flange on one inner end face of the cylinder, and a groove along the inner circumference near the other end face, and a stop ring is formed in this groove. The substrate is mounted so that the center axis of the substrate is aligned with the center axis of the tray body between the ring-shaped flange portion and the stop ring of the tray body, and the substrate is mounted in a direction perpendicular to the substrate surface. Is provided with a substrate retainer movably held, a sliding member installed to receive an axial force, and a spring, and the spring is used to move the sliding member to the substrate retainer or a ring-shaped flange. 2. The substrate transport tray according to claim 1, wherein the substrate attached to the substrate retainer is constantly urged toward the mounting surface of the substrate holder while the substrate is held in sliding contact with the substrate holder.