JPH0745523A - Semiconductor substrate heating equipment of vacuum chamber - Google Patents

Abstract

PURPOSE:To enable the multistage temperature setting of a wafer and stably maintain the set temperature, in a wafer heating equipment in a vacuum chamber of a sputtering equipment, a low pressure CVD equipment, etc. CONSTITUTION:A heating lamp 7 for obtaining a desired set temperature from the low temperature side, a cooling mechanism which brings a block 3 into contact with the rear of a substrate holder 1 and decreases a temperature to a set value from the high temperature side, and a high temperature side control equipment 16a and a low temperature side control equipment 16b which control the temperature of inert gas at a set value are installed, and the temperature of a wafer 20 is set to be a specified value by heating or cooling the substrate holder 1 which almost airtightly mounts a wafer 20, by turning on or off the heating lamp 7 or by contacting or separating the block 3 of the cooling mechanism. Further the temperature of the wafer is set to be a specified value, by filling a closed space formed by the wafer 20 and the substrate holder 1 with inert gas whose temperature is set to be a specified value by the temperature control equipments 16a, 16b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor substrate heating apparatus in a decompression chamber in which a semiconductor substrate is housed and surface-treated in a sputtering apparatus, a low pressure CVD apparatus or the like.

[0002]

2. Description of the Related Art Generally, when forming a thin film on a semiconductor substrate (hereinafter simply referred to as a wafer), it is known that the temperature of the wafer influences the quality of the film formed. For this reason, a heating device for controlling the temperature of the wafer is provided in a decompression chamber such as a sputtering device or a decompression CVD device. From the viewpoint of productivity, various improvements have been proposed for these heating devices, such as rapid temperature rise / fall of the wafer and improvement of the film quality, such as temperature distribution accuracy.

FIG. 2 is a schematic cross-sectional view showing an example of a conventional wafer heating apparatus. Among the heating devices of this type, a heating device that changes the temperature in a plurality of stages in a short time is disclosed in JP-A-62-35.
It is disclosed in Japanese Patent Publication No. 517. This heating device is applied to a sputtering device, and as shown in FIG.
A heating lamp 26 attached to one side surface of a decompression chamber 24 connected to a load lock chamber via a gate valve 23 for heating the wafer 20 and a cooling member at the tip of the inside of the revolution mechanism 21 and moved in the direction of the arrow. And a substrate cooling mechanism 2 for contacting the cooling member with the back surface of the wafer 20 to absorb heat.
2 and.

This heating mechanism is designed for the purpose of treating the surface of a wafer having a temperature difference in a short time. The wafer 20 is heated from a high temperature to a low temperature in a shorter time. For this purpose, the substrate cooling mechanism 22 is provided.

In the operation of the sputtering apparatus having this heating device, first, the wafer 20 transferred to the decompression chamber 24 at a temperature which does not change from room temperature is rotationally moved from the position A to the position B by the revolution mechanism 21, and the heating lamp is used. Wafer 20 at 26
Is heated to 400 ° C., for example. Next, the wafer 20 is moved to the position C and the first film forming process is performed while facing the cathode 27. Then, when the first film forming process is completed, the wafer 20 is positioned at the position D by the rotation of the revolution mechanism 21, and the cooling member of the substrate cooling mechanism 22 moves in the direction of the arrow and contacts the back surface of the wafer. As a result, the wafer 20 is cooled,
The film is cooled to a temperature required for the film forming process, for example, a low temperature of 100 ° C. Then, the second film forming process is performed while facing the cathode 28.

As described above, the heating device is provided with the cooling means for cooling the wafer set at the high temperature faster.
It improves the throughput of sputtering equipment.

[0007]

However, in the above-described conventional heating device, since the heating lamp and the substrate cooling mechanism are arranged at different places, the process for changing the temperature from high temperature to low temperature in two steps is required. Although applicable, it is difficult to apply to a process in which there are two or more stages of temperature difference and there are three stages of transition from high temperature to low temperature and from low temperature to high temperature. Further, even in the same two steps, in the process of shifting from low temperature to high temperature, it is possible by changing the indexing method of the revolution mechanism, but there is a drawback that the throughput of the sputtering apparatus deteriorates. Furthermore, to set the temperature to a low temperature, the water-cooled cooling member is brought into contact with a hot wafer to absorb the heat of the wafer and lower the temperature, but the residual heat of the surrounding members where the wafer is placed and the heat from residual molecules As a result, the temperature is transmitted to the wafer, causing a temperature change, which makes it difficult to stably maintain the wafer at the set temperature.

Therefore, an object of the present invention is to provide a wafer heating device in a decompression chamber which can set the temperature of a wafer in multiple stages and can stably maintain the set temperature.

[0009]

A feature of the present invention is that it has a closed space consisting of a flat mounting surface for mounting a peripheral portion of a semiconductor substrate in a decompression chamber and a back surface of the semiconductor substrate, and the closing space. A substrate holder in which a blowout hole for supplying an inert gas to the space is formed, locking means for holding the mounted semiconductor substrate and fixing it to the substrate holder, and arranged to face the back surface of the substrate holder and spaced apart from each other. A heating means for heating the substrate holder, a cooling mechanism for absorbing heat of the substrate holder by bringing a cooling member into contact with or away from the back surface of the substrate holder, and the inert gas supplied from an inert gas source. A semiconductor substrate heating apparatus for a decompression chamber, comprising at least two temperature controllers having different gas temperatures, and switching means for allowing one of these temperature controllers to pass through the blowout hole.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view of a wafer heating apparatus in a decompression chamber showing an embodiment of the present invention. As shown in FIG. 1, this wafer heating apparatus has a flat mounting surface on which a peripheral portion of the wafer 20 is mounted in the decompression chamber 24a and the wafer 20.
The substrate holder 1 having a closed space 1b on the back side thereof and having a plurality of blow-out holes 1a for supplying an inert gas to the closed space 1b, and the mounted wafer 20 are fixed to the holding substrate holder 1. Ring-shaped pressing plate 12 and air cylinders 13a, 13 for vertically moving the pressing plate 12
b, a heating lamp 7 facing the back surface of the substrate holder 1 and spaced apart from each other, and a heating lamp 7 for heating the substrate holder 1, and a cooled block 3 on the back surface of the substrate holder 1 are brought into contact with or separated from each other so that the substrate holder 1 Substrate holder cooling mechanism for absorbing heat, and air cylinders 14a, 14b for vertically moving the block 3
And two temperature controllers 16a and 16b for high temperature and low temperature which can respectively change the temperature of the inert gas supplied from the gas supply source 10 within a predetermined temperature range, and these temperature controllers 16a, 16a,
A switching valve 9 that allows one of the pipes 16b and the pipe 2 to pass therethrough;
The temperature signal from the thermocouple 6 embedded in the substrate holder 1 is input to control the operation of the cooling mechanism and the on / off of the heating lamp 7, and set the gas flow rate and temperature of the temperature controllers 16a and 16b and the operation of the switching valve. The control unit 5 for controlling

The substrate holder cooling mechanism includes a jacket 4 for storing cooling water, bellows pipes 11a and 11b mounted on the jacket 4 and expandable and contractible, and bellows pipes 11a and 11b.
A ring-shaped block 3 is attached to one end of 11b in a watertight manner, and air cylinders 14a and 14b are connected to the block 3 via a piston rod. Then, the block 3 moves in the directions of arrows A and B by the operation of the air cylinders 14a and 14b to come into contact with or separate from the substrate holder 1. Here, it is preferable that a constant temperature bath and a circulation pump are provided outside the apparatus so that the cooling water having a constant temperature in the jacket 4 can be circulated.

In the present invention, in addition to the lamp heating mechanism and the substrate holder cooling mechanism, a gas temperature switching mechanism that uses an inert gas as a heat transfer medium is newly provided. This gas temperature switching mechanism has a temperature controller 16a having two systems of a high temperature part and a low temperature part.
16b, and this temperature controller 16a, 16b
Although not shown in the drawing, high temperature and low temperature reservoirs for storing the gas supplied from the gas supply source 10, heaters and chiller units for changing the temperature of the gas in the respective reservoirs, and gas flow rate adjustment Equipped with a flow control valve. Furthermore, these temperature controllers 16a and 16b are controlled by signals from the control unit 5 to set the temperature control and flow rate control of the gas.

The inert gas supplied from one of the temperature controllers 16a and 16b is brought to a desired set temperature, passes through the blow-out hole 1a and fills the closed space 1b between the wafer 20 and the substrate holder 1, and the closed space. The wafer 20 is brought to a preset temperature by increasing the concentration of gas molecules of 1b to increase the heat transfer rate. In order to increase the concentration of the gas molecules, the flow rate control valve is adjusted and the pressure is preferably set to about 70 Torr.
Then, in order to limit the pressure so that the wafer 20 is not deformed by an excessive increase in pressure, it is necessary to provide a relief valve 16 set to a critical pressure in the middle of the path of the pipe 2.

Here, the leakage of gas from the closed space 1b was considered. Normally, the pressure in the decompression chamber 24a varies depending on the device, but is 1 Torr to 8 mTo.
The wafer 20 and the substrate holder are evacuated by a vacuum pump having a relatively large evacuation capacity so as to maintain the above pressure constantly while introducing an inert gas from the gas introduction port of the decompression chamber. It was concluded that the leak amount from the gap between the flat-finished mounting surface and the mounting surface of No. 1 is almost negligible.

Next, the operation of this wafer heating apparatus will be described assuming a process of setting the wafer temperature in two steps. First set to high temperature of 400 ° C, then 10
The case of setting at 0 ° C. will be described again with reference to FIG.

First, the wafer 2 is placed on the mounting surface of the substrate holder 1.
0 is put on, the air cylinders 13a and 13b are operated, and the wafer 20 is fixed by the pressing plate 12 to the extent of being almost airtight.
Next, the decompression chamber 24a is evacuated and Ar gas is introduced from the gas introduction port to maintain the pressure of the decompression chamber 24a at about 0.1 Torr. Next, the heating lamp 7 is turned on, and at the same time, the high temperature temperature controller 16a is operated to blow out Ar gas heated to 400 ° C. from the hole 1a. After a predetermined time, the heating lamp 7 is automatically turned on or off so that the temperature measured by the thermocouple 6 becomes 400 ° C. But 400
Ar gas at ° C continues to be supplied. Then, the first film deposition process is performed on the wafer 20 kept at 400 ° C.

Next, when the first film forming process is completed, the opening / closing valve 8 is closed, the supply of Ar gas is stopped, and the air cylinders 14a and 14b are operated to bring the block 3 into contact with the back surface of the substrate holder 1. At the same time, the switching valve 9 is operated to switch to the temperature controller 16b on the low temperature side and the opening / closing valve 8 is opened. As a result, the Ar gas preset at 100 ° C. is supplied from the blowout hole 1a. And the thermocouple 6 is 100 ° C
The heating lamp 7 is automatically turned on or off. On the other hand, the Ar gas having a temperature of 100 ° C. is continuously supplied to maintain the temperature of the wafer 20 at 100 ° C. Then, the second film forming process is completed.

On the contrary, when setting the temperature of the wafer from a low temperature to a high temperature, first, the air cylinders 14a, 14b.
Is activated to bring the block 3 into contact with the rear surface of the substrate holder 1, turn on the heating lamp 7, and at the same time supply Ar gas at 100 ° C. from the temperature controller 16b on the low temperature side.
The heating lamp 7 is automatically turned on or off to reach C, and the wafer 20 is heated by Ar gas from the temperature controller 16b. Then, the second film forming process is completed. Next, the heating lamp 7 is turned on, and at the same time, the temperature controller 1 on the high temperature side is turned on.
6a is switched to, and Ar gas warmed to 400 ° C. is supplied. Then, the heating lamp 7 is automatically turned on or off so that the temperature of the thermocouple 6 becomes 400 ° C.
The wafer 20 is stabilized at 4 ° C by supplying Ar gas at 4 ° C.
Maintained at a temperature of 00 ° C. Then, the first film forming process is performed.

[0020]

As described above, according to the present invention, the heating means for raising the temperature from the low temperature side to the desired set temperature, the cooling means for lowering the temperature from the high temperature side to the low temperature side, and the temperature control for adjusting the inert gas to the set temperature. And a substrate holder on which a wafer is mounted in a substantially airtight manner is heated or cooled to substantially the preset temperature, and the closed space formed by the wafer and the substrate holder is filled with an inert gas at the preset temperature. This has the effect of maintaining the wafer at a stable set temperature.

Further, by providing a plurality of temperature controllers having different set temperatures, the temperature of the wafer can be changed by arbitrarily switching the temperature controllers even in a process having multi-step set temperatures with different temperatures, or from high temperature to low temperature and from low temperature to high temperature. There is also an effect that various can be set.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a wafer heating device in a decompression chamber showing an embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view showing an example of a conventional wafer heating apparatus.

[Explanation of symbols]

 1 Substrate holder 1a Blow-out hole 1b Closed space 2 Piping 3 Block 4 Jacket 5 Control part 6 Thermocouple 7,26 Heating lamp 8 On-off valve 9 Switching valve 10 Gas supply source 11a, 11b Bellows piping 12 Presser plate 13a, 13b, 14a, 14b Air cylinder 15 Relief valve 16a, 16b Temperature controller 20 Wafer 21 Revolution mechanism 22 Substrate cooling mechanism 23 Gate valve 24, 24a Decompression chamber 27, 28 Cathode

Claims (1)

[Claims] 1. A blowout hole for supplying an inert gas to the closed space, the closed space having a flat mounting surface for mounting a peripheral edge of the semiconductor substrate in the decompression chamber and a back surface of the semiconductor substrate. A substrate holder on which a substrate is formed, locking means for holding the mounted semiconductor substrate and fixing it to the substrate holder, and heating means for heating the substrate holder, which is arranged facing the back surface of the substrate holder and spaced apart from each other. A cooling mechanism that absorbs heat of the substrate holder by bringing a cooling member into contact with or away from the back surface of the substrate holder, and at least two temperature controls for different temperatures of the inert gas supplied from the inert gas source. A vessel,
A semiconductor substrate heating apparatus for a decompression chamber, comprising any one of these temperature regulators and a switching means for passing through the blowout hole.