JP2778574B2 - Semiconductor manufacturing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a semiconductor manufacturing apparatus, and more particularly to a semiconductor manufacturing apparatus such as a plasma CVD apparatus and a plasma etching apparatus.

[0002]

2. Description of the Related Art A plasma CVD method using a material gas such as TEOS, SiH ₄ or O ₂ is widely used for forming an insulating film. There are two types of plasma CVD chambers: single-wafer and batch. Since it is difficult to control the process parameters of each semiconductor wafer in a batch chamber, single-wafer is the mainstream in the future as semiconductor wafers become larger. It is considered to be.

FIG. 9 is a sectional view showing an example of a conventional single-wafer plasma CVD apparatus. As shown in FIG. 9, the single-wafer plasma CVD apparatus includes a process chamber 37 having a process chamber body 4 and a process chamber lid 5,
The process chamber 37 and the wafer transfer chamber 32 are separated by the gate valve 9.

A wafer transfer robot 13 driven by a wafer transfer robot drive unit 15 is provided in a wafer transfer chamber 32 sealed by the outer wall 7 of the wafer transfer chamber. The heater block 16, the wafer transfer upper and lower pins 21, the susceptor 1, and the shower head 2 are provided, and the susceptor 1 and the shower head 2 are bolted to predetermined positions.
It is fixed at 5.

Next, the operation will be described. The semiconductor wafer 3 is set on the fork 11 of the wafer transfer robot 13, and the wafer transfer chamber 32 is evacuated through the wafer transfer chamber exhaust port 28. Wafer transfer chamber 3
After the pressure of the chamber 2 becomes the same as that of the process chamber 37 evacuated through the process chamber exhaust port 26, the gate valve 9 is opened. The fork 11 of the wafer transfer robot 13 extends toward the process chamber 37, and the semiconductor wafer 3 is carried into the process chamber 37. At this time, the wafer upper and lower pins 21 driven by the upper and lower pin driving units 23 slide upward, and the wafer transfer robot 13 places the semiconductor wafer 3 on the pins and returns into the wafer transfer chamber 32. Thereafter, the gate valve 9 is closed, and the wafer upper and lower 21 slide up and down, and the semiconductor wafer 3 is placed on the susceptor 1. Next, a process gas is introduced into the process chamber 37 through a number of holes of the shower head 2 from the gas inlet 29, and a high-frequency output is applied between the susceptor 1 and the shower head 2 to form an insulating film on the semiconductor wafer 3. Let it grow. After the growth is completed, the semiconductor wafer 3 is unloaded from the process chamber 37 in the reverse order of loading the wafer. Further, a cleaning gas is passed through a number of holes of the shower head 2 and a high frequency output is applied between the susceptor 1 and the shower head 2 to remove a film grown in the process chamber 37.

[0006]

In this conventional single-wafer plasma CVD apparatus, replacement of the deteriorated susceptor and shower head involves returning the process chamber to atmospheric pressure, lowering the temperature of the heater block, and then opening the chamber lid. The bolts fixing the susceptor and the shower head are removed. However, this operation exposes the inner wall of the process chamber to oxygen and moisture in the atmosphere. The oxygen content and the moisture react with the residual gas adsorbed on the inner wall of the process chamber. In addition, oxygen and moisture are adsorbed on the inner wall of the process chamber. In addition, by lowering the heater temperature,
Since the temperature inside the process chamber changes greatly, the products formed on the inner wall of the chamber are peeled off due to the difference in the heat shrinkage rate with the inner wall of the chamber. These phenomena cause particle generation and film quality fluctuation. At present, measures are taken by wiping and cleaning the inner wall of the chamber with ethanol.However, the work is difficult, and there is a problem that the wiping and cleaning cannot completely remove generated particles and oxygen and moisture attached to the inner wall of the chamber. Was.

On the other hand, CVD of chemical semiconductors such as GaAs
For example, Japanese Patent Application Laid-Open No. Hei 4-360523 discloses a method in which a chamber for setting a susceptor is provided below a process chamber, and a lower surface of a chamber called a susceptor and a skirt is replaced in a vacuum. However, applying this method to a single-wafer plasma CVD apparatus involves a structural problem that the lower part of the susceptor serving as a heater and an electrode has a complicated structure, and there is no space for providing a chamber for setting the susceptor. Even if a space for securing the space and setting the susceptor is provided, replacement in a clean state cannot be performed due to a problem described below.

In the present single-wafer plasma CVD apparatus, once the susceptor is replaced, the surface temperature of the susceptor changes even if the heater is controlled to the same temperature before and after the replacement. This is because the amount of heat conduction from the heater to the susceptor changes due to a change in the area of the contact surface between the aluminum susceptor and the aluminum heater block.

The contact area between the susceptor and the heater is affected by the unevenness on the lower surface of the susceptor and the contact load of the susceptor on the heater block. In order to suppress the change in the surface temperature of the susceptor due to the unevenness of the lower surface, which differs for each susceptor, the susceptor must be brought into pressure contact with the heater block at a certain constant pressure. However, conventionally, the means is bolting from the inside as shown in FIG.
This pressure contact cannot be made in a vacuum state. In other words, the technique disclosed in Japanese Patent Application Laid-Open No. Hei 4-360523 can only transfer the susceptor to the process chamber in a vacuum. Therefore, it is possible to remove the susceptor that has been bolted so far. It cannot be set by contacting with pressure. In addition, since the shower head attached to the lower surface of the lid has conventionally been bolted from the inside, the above-described conventional technique, which only transports in a vacuum, cannot be applied to replacement of a shower head of a single-wafer plasma CVD apparatus. That is, even if the above-described conventional technique is used for a single-wafer plasma CVD apparatus, the susceptor or the shower head must be returned to the atmosphere after being transported in a vacuum and a predetermined mounting must be performed. This does not solve the problem of residual gas and the problem of the product peeling off from the inner wall of the chamber.

Accordingly, an object of the present invention is to carry out the transfer and the predetermined mounting of a susceptor or shower head to be replaced in a vacuum, thereby exposing the process chamber to the atmosphere when replacing the susceptor or shower head. It is an object of the present invention to provide a semiconductor manufacturing apparatus which has been removed.

[0011]

SUMMARY OF THE INVENTION An apparatus according to the present invention comprises a susceptor for processing a semiconductor wafer, a susceptor for a lower electrode on which the semiconductor wafer is mounted, and a showerhead for an upper electrode for dispersing a supply gas onto the semiconductor wafer. A process chamber, an electrode replacement chamber adjacent to the process chamber via a gate valve, and the inside of which can be evacuated, so that the susceptor and / or the showerhead can be replaced in a vacuum; An electrode transfer robot that transfers the susceptor or the shower head from the replacement chamber to the process chamber in a vacuum, and an electrode that transfers the susceptor or the shower head to a predetermined height in the process chamber. It has upper and lower pins.

Preferably, the apparatus further comprises a clamp mechanism for fixing the susceptor and / or the shower head with a predetermined torque from outside the process chamber.

Preferably, a copper plate is attached to the heater block contact surface of the susceptor. In addition, a first stage for mounting the susceptor or showerhead used up to now and a second stage for mounting the susceptor or showerhead to be used can be provided in the electrode replacement chamber. Further, the periphery of the susceptor on the side in contact with the heater block has a U shape, into which the protrusion of the clamp mechanism enters, and by the torque outside the process chamber, through the protrusion. The susceptor can be brought into pressure contact with the heater block. Alternatively, the periphery of the shower head on the side opposite to the side facing the semiconductor wafer has a U-shape, and the protrusion of the clamp mechanism enters therein, and the protrusion outside the process chamber is used to reduce the protrusion. The showerhead can be brought into pressurized contact with the outer wall of the process chamber through the intermediary of the showerhead.

As described above, according to the present invention, since the electrode replacement chamber is provided adjacent to the process chamber via the gate valve and the inside of which is evacuated, the susceptor or the shower head can be transferred in a vacuum, and the susceptor is placed in the process chamber. Alternatively, since the upper and lower electrodes for transporting the shower head to a predetermined height are provided, the susceptor or the shower head can be removed in a vacuum.

[0015]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a cross-sectional view showing an embodiment of the present invention, in which the present invention is applied to a semiconductor manufacturing apparatus, and FIG. 2 is a plan view showing a main part thereof. In this semiconductor manufacturing apparatus, the wafer transfer chamber 32 and the process chamber 30 are horizontally arranged via a vacuum gate valve 9, and the process chamber 30 and the electrode replacement chamber 31 are horizontally arranged via a vacuum gate valve 8. It is configured to be arranged.

The wafer transfer chamber 32 is operated by the gate valve 9 as in the prior art shown in FIG.
The inside surrounded by the outer wall 7 of the wafer transfer chamber is evacuated by an exhaust system (not shown) through the exhaust port 28 of the wafer transfer chamber. A wafer transfer robot 13 driven by a wafer transfer robot drive unit 15 is provided inside the semiconductor wafer 3. The semiconductor wafer 3 is placed on the fork 11 of the wafer transfer robot 13 in a vacuum, and the gate valve 9 in an open state is opened. The semiconductor wafer 3 is conveyed to the process chamber 30 under vacuum, performs a predetermined process by closing the gate valve 9, and places the processed semiconductor wafer 3 on the fork 11 through the gate valve 9 in the open state. It returns to the transfer chamber 32.

The process chamber 30 of the present invention is separated from the wafer transfer chamber 32 and the electrode replacement chamber 31 by the gate valve 9 and the gate valve 8, respectively.
The inside sealed by the process chamber lid 5 abutting through the ring 25 is evacuated by an exhaust system (not shown) through a process chamber exhaust port 26. A susceptor 1 on which a semiconductor wafer 3 is placed and which serves as a lower electrode, and a wafer heater block 1 with a built-in heater for contacting the susceptor 1 and heating the semiconductor wafer 3 are provided therein.
6 and a shower head 2 of an upper electrode for spraying a supply gas introduced from a gas inlet 29 onto the semiconductor wafer 3.

The susceptor 1 of the present invention comprises a heater block 1
6, a U-shape around the lower side
Are formed, and the protrusion 17A at the tip of the susceptor clamp 17 enters therein. The susceptor clamp 17 penetrates the main body 4 constituting the outer wall through the vacuum seal 24 and is led out to the outside. The susceptor clamp 17 is connected to the susceptor tightening handle 18 to constitute a susceptor clamp mechanism 40, and the susceptor 1 is heated with a predetermined torque. The pressure is fixed to the block 16. The susceptor clamp mechanism 40 will be described later with reference to FIG.

Similarly, in the shower head 2, a U-shape 2 A is formed on the side opposite to the side facing the semiconductor wafer 3, that is, on the upper periphery, and the shower head clamp 19 is formed there.
The projecting portion 19A at the tip of is inserted. The shower head clamp 19 penetrates the lid 5 constituting the outer wall through the vacuum seal 24 and is led out to the outside. The shower head clamp 19 is connected to the shower head tightening handle 20 to form a shower head clamp mechanism 41, and the shower head clamp mechanism 41 has a predetermined torque. 2 is fixed to the lid 5 under pressure. The shower head clamp mechanism 41 will be described later with reference to FIG.

Further, in the present invention, apart from the wafer transfer upper and lower pins 21 which are coupled to the wafer transfer upper and lower pin drive unit 23 to move the semiconductor wafer 3 up and down, the electrode upper and lower pin drive units 43
An electrode upper and lower pin 22 for transporting a susceptor or shower head to be attached or detached by driving vertically at a predetermined height is provided through the heater block 16.

The electrode replacement chamber 31 is separated from the process chamber 30 by the gate valve 8, and the inside surrounded by the electrode replacement chamber outer wall 6 is evacuated by an exhaust system (not shown) through the electrode replacement chamber exhaust port 27. Is drawn. The electrode transport robot 12 driven by the electrode transport robot drive unit 14 is provided inside the electrode transport robot 12.
And a susceptor 1 attached to or detached from the fork 10 of the electrode transfer robot 12 in a vacuum.
Alternatively, the shower head 2 is placed and transported to the process chamber 30 under vacuum through the gate valve 8 in the open state, or transported from the process chamber 30.

FIG. 1 illustrates the transfer of the susceptor 1, but the transfer of the shower head 2 is the same.
The shower head 2 is placed on the fork 10 in the same direction (vertical direction) as the mounting direction in the process chamber 30.

Next, an electrode replacing operation in the semiconductor manufacturing apparatus will be described with reference to FIGS. Note that the operations of the semiconductor wafer 3 in the wafer transfer chamber 32 and the process chamber 30 are the same as those in the related art, and thus the description is omitted.

In mounting the susceptor 1, the susceptor 1 is first set on the fork 10 of the electrode transport robot 12, and the electrode replacement chamber 31 is evacuated. When the pressure becomes equal to that of the process chamber 30, the gate valve 8 is opened. The fork 10 of the electrode transport robot 12 is extended to the process chamber 30 and the susceptor 1 is carried into the process chamber 30. At this time, the electrode upper and lower pins 22 are slid upward, and the electrode transfer robot 12 places the susceptor 1 on the electrode upper and lower pins 22 to be in the state of FIG. The fork 10 returns to the electrode replacement chamber 31 and closes the gate valve 8. The electrode upper and lower pins 22 are lowered, and the susceptor 1 is placed on the heater block 16.

In order to fix the susceptor 1 placed on the heater block 16 to the heater 16, the susceptor clamp 17 is
Rotate 80 degrees. Tip 17A of susceptor clamp 17
Is shaped like a hook and, when rotated 180 degrees, is hooked on a U-shape 1A on the outer peripheral portion of the susceptor 1;
The state shown in FIG. In order to fix the susceptor 1 with a constant load, the rotation angle of the susceptor clamp 17 is kept constant.
Turn the susceptor clamp tightening handle 18.

As shown in the susceptor clamp mechanism 40 of FIG. 4, the susceptor clamp 17 and the susceptor clamp tightening handle 18 are screwed. The susceptor clamp tightening handle 18 rotates but does not slide in the vertical direction. Conversely, the susceptor clamp 17 slides in the vertical direction but does not rotate more than 180 degrees. By turning the susceptor clamp tightening handle 18, the susceptor clamp slides downward and the susceptor 1
Is pressed against the heater block side. By controlling the tightening torque of the susceptor clamp tightening handle 18, the susceptor 1 comes into contact with the heater 16 with a constant load.

The above is the mounting operation of the susceptor 1 to be used in a vacuum. The operation of removing the susceptor 1 used in a vacuum may be performed in the reverse of the above operation. The susceptor 1 used up to now, which has been removed in a vacuum, can be mounted in the electrode replacement chamber 31 in the vacuum in the susceptor 1 to be used. Alternatively, the detached susceptor 1 which has been used up to now is closed, the valve 8 is closed, the susceptor 1 is taken out of the electrode replacement chamber 31, and the electrode replacement chamber 31 in which the susceptor 1 to be used is set is evacuated. The above mounting operation may be performed. During the latter series of operations, the gate valve 8 is closed, so that the process chamber 30 maintains a vacuum state.

FIGS. 1 to 3 show a state where the shower head 2 is already mounted.
4 is also the same as that of the susceptor 1. In FIG. 4, each part of the shower head clamp mechanism 41 corresponding to the susceptor clamp mechanism 40 is shown in parentheses.

When both the susceptor 1 and the shower head 2 are exchanged, first, the susceptor 1 is removed, the shower head 2 is removed, the shower head 2 is attached, and the susceptor 1 is attached.

When replacing only the shower head 2,
The susceptor 1 is temporarily removed, and temporarily held in the electrode replacement chamber 31.

When only the susceptor 1 is replaced, the procedure described above may be used.

Here, it is preferable that a copper plate 34 is attached to the lower surface of the susceptor 1 as shown in FIG. Since the copper plate 34 is softer than the aluminum constituting the susceptor 1 and the heater block 16, if the susceptor 1 is tightened to the heater 16 with a strong load, the copper is deformed into the shape of the surface of the heater 16 as shown in FIG. The contact of the heater 16 is almost completely performed, and the change in the contact area due to the replacement of the susceptor 1 is smaller than that of the susceptor without the copper plate 34.

FIG. 7A is a graph comparing the change in the contact area between the susceptor 1 and the heater block 16 due to the replacement of the susceptor 1 with and without the copper plate.
By attaching the copper plate 34 to the lower surface of the susceptor, the contact area between the susceptor 1 and the heater block 16 is stabilized with respect to susceptor replacement.

FIG. 7B is a graph comparing the change in the susceptor surface temperature with and without the copper plate due to the replacement of the susceptor 1. Similarly to the contact area, it can be seen that the susceptor surface temperature is stabilized by attaching the copper plate 34 to the lower surface of the susceptor.

FIG. 8 is a view showing an application example of the electrode replacement chamber of FIG. In order to perform electrode replacement in this semiconductor manufacturing apparatus in a short time, two stages 36 for mounting a susceptor or a shower head in the electrode replacement chamber 31 were provided as shown in FIG. When replacing the susceptor 1, the replacement susceptor 1 is placed on one of the two stages 36A, and the electrode replacement chamber 31 is evacuated. Then, the deteriorated susceptor 1 is removed by the same operation as the operation described with reference to FIGS. 1 to 3 (the operation opposite to the mounting operation), and the electrode transfer robot 12 places the susceptor 1 on the vacant stage 36B. In order to mount a new susceptor, the susceptor 1 previously mounted on the stage 36A is picked up by the electrode transfer robot 12, transported to the process chamber 30, and mounted by the operations described with reference to FIGS. Susceptor 1
Since the operation from removal to attachment can be performed without setting the electrode replacement chamber 31 to the atmospheric pressure, the replacement time of the susceptor 1 can be reduced.

When the shower head 2 is replaced, the stage 36A and the stage 36B can be used similarly.

In consideration of replacing both the susceptor 1 and the shower head 2, it is more preferable to provide two stages 36A and two stages 36B.

The present invention is not limited to the above-described embodiment.
And a batch-type apparatus for processing a plurality of wafers at a time.

[0040]

As described above, according to the present invention, the susceptor or the shower head is conveyed in a vacuum because the electrode replacement chamber is provided adjacent to the process chamber via the gate valve and has a vacuum inside. Can be.
Further, an electrode upper and lower pins for transferring the susceptor or the shower head to a predetermined height are provided in the process chamber, and a clamp mechanism for fixing the susceptor or the shower head with a predetermined torque from outside the process chamber is provided. Removal and pressure fixing can also be performed in vacuum. Therefore, it is possible to replace the susceptor while suppressing a change in the surface temperature thereof without causing a problem of a residual gas due to oxygen or moisture in the atmosphere, a problem of particle generation, and a problem of products falling off from the inner wall of the chamber. Alternatively, the showerhead can be fixed on top. Further, by attaching a copper plate to the contact surface of the aluminum susceptor that comes into contact with the aluminum heater block, a change in the susceptor surface temperature due to susceptor replacement can be further suppressed.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a semiconductor manufacturing apparatus according to an embodiment of the present invention.

FIG. 2 is a plan view showing a main part of FIG.

FIG. 3 is a diagram for explaining the operation of the process chamber section shown in FIG.

FIG. 4 is an enlarged sectional view of the clamp mechanism shown in FIG. 1;

FIG. 5 is a sectional view showing a case where the susceptor shown in FIG. 1 is further improved.

6 is a sectional view including a partially enlarged sectional view showing a contact state between the susceptor and the heater block shown in FIG. 5;

7A and 7B are diagrams showing an effect of the susceptor of FIG. 5, and FIG.
Shows the relationship between the contact area of the susceptor and the heater due to the replacement of the susceptor, and (B) shows the relationship between the surface temperature of the susceptor after the replacement of the susceptor.

FIG. 8 is a sectional view showing a case where a part of FIG. 1 is modified.

FIG. 9 is a sectional view showing a conventional single-wafer plasma CVD apparatus.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 susceptor 2 shower head 3 semiconductor wafer 4 process chamber main body 5 process chamber lid 6 electrode replacement chamber outer wall 7 wafer transfer chamber outer wall 8 gate valve 9 gate valve 10 fork 11 fork 12 electrode transfer robot 13 wafer transfer robot 14 electrode transfer robot drive Unit 15 Wafer transfer robot drive unit 16 Wafer heating heater block 17 Susceptor clamp 18 Susceptor clamp tightening handle 19 Shower head clamp 20 Shower head clamp tightening handle 21 Wafer transfer upper and lower pins 22 Electrode upper and lower pins 23 Wafer transfer upper and lower pin drive unit 24 Vacuum seal 25 O-ring 26 Process chamber exhaust port 27 Electrode replacement chamber exhaust port 28 Wafer transfer chamber exhaust port 29 Gas guide Mouth 30, 37 process chamber 31 electrode replacement chamber 32 wafer transfer chamber 33 the bellows 34 copper 35 volts 36A, 36B stage 40 susceptor clamp mechanism 41 showerhead clamping mechanism 43 electrode vertical pin drive unit

Continuation of the front page (51) Int.Cl. ⁶ identification code FI H01L 21/68 H01L 21/68 N 21/302 B (58) Investigated field (Int.Cl. ⁶ , DB name) H01L 21/31 H01L 21 / 205 H01L 21/3065 H01L 21/68 C23C 16/50 C30B 25/12

Claims (6)

(57) [Claims] 1. A process chamber for processing a semiconductor wafer, comprising: a susceptor serving as a lower electrode on which the semiconductor wafer is mounted; and a showerhead serving as an upper electrode for distributing a supply gas onto the semiconductor wafer. In a semiconductor manufacturing apparatus having a chamber, an electrode replacement chamber adjacent to the process chamber via a gate valve and capable of being evacuated so that the susceptor and / or the shower head can be replaced in a vacuum, Located in the electrode replacement chamber,
An electrode transfer robot that transfers the susceptor or the shower head from the replacement chamber to the process chamber in a vacuum, and an electrode upper and lower pin that transfers the susceptor or the shower head to a predetermined height in the process chamber are provided. A semiconductor manufacturing apparatus. 2. The semiconductor manufacturing apparatus according to claim 1, further comprising a clamp mechanism for fixing said susceptor or said shower head from outside of said process chamber with a predetermined torque. 3. A susceptor having a copper plate attached to the heater block contact surface thereof.
The semiconductor manufacturing apparatus according to the above. 4. A first stage for mounting the susceptor or the showerhead which has been used up to now and a second stage for mounting the susceptor or the showerhead to be used in the electrode replacement chamber. The semiconductor manufacturing apparatus according to claim 1, 2 or 3, wherein: 5. The U-shaped periphery of the susceptor on the side in contact with the heater block, into which a protrusion of the clamp mechanism enters, and the protrusion is formed by a torque outside the process chamber. 3. The semiconductor manufacturing apparatus according to claim 2, wherein the susceptor is brought into pressure contact with the heater block via a heater. 6. A periphery of the shower head on the side opposite to the side facing the semiconductor wafer has a U-shape, into which a protrusion of the clamp mechanism enters, and the torque is generated outside the process chamber by the torque. 3. The semiconductor manufacturing apparatus according to claim 2, wherein the shower head is brought into pressure contact with an outer wall of the process chamber via a protrusion.