JP2000216092A - Degassing process system in manufacturing semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a degassing process system having a good efficiency. SOLUTION: The degassing process system comprises a holder for holding a wafer 5 at a high temp. in a wafer dehydrating chamber 6 and an exhaust device 2 for degassing the wafer 5 heated at the high temp. A cryo-panel is provided between the wafer dehydrating chamber 6 and the exhaust device 2, a reductive, dehydrative or rare gas or a mixed gas thereof is inserted at a specified pressure in this chamber 6, and the wafer 5 heated at a high temp. is efficiently degassed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a degassing method for dehydrating a wafer in the manufacture of semiconductor devices.
In particular, it relates to an efficient degassing method.

[0002]

2. Description of the Related Art In a conventional degassing system, only a rare gas is used, and degassing is performed for a long time at a vacuum of 10 ^-3 Torr or less.

FIG. 2 is a schematic diagram showing the structure of a conventional degassing system. In this method, a wafer 5 having an interlayer film is sent to a pre-processing chamber via a load lock. At this time, the preprocessing chamber is a wafer dehydration processing chamber 6 having a chamber configuration having a gate valve with a small capacity. The chamber 6 includes a holder capable of raising the substrate temperature to about 500 ° C. and a cryopump 12 as an exhaust device.
And The shield 3 around the holder increases conductance and improves exhaust characteristics. Also,
As described above, only rare gas was used as the gas to be injected into the chamber 6, and the degree of vacuum was 10 ⁻³ Torr or less.

[0004]

In the above-mentioned conventional example,
When degassing is performed in a vacuum, gas molecules are exhausted by diffusion, so that water molecules and the like that have once desorbed adhere to the wafer or the apparatus wall, and degassing cannot be performed effectively. Therefore, long-time annealing is required to perform sufficient degassing. Therefore, there is a problem that it takes time to degas.

[0005] Therefore, an object of the present invention is to provide a degassing system for performing efficient degassing in order to solve the above problems.

[0006]

In order to achieve the above object, a degassing method according to the present invention comprises a holder for increasing a wafer temperature in a wafer dehydration processing chamber used for manufacturing a semiconductor device; In a degassing method including an exhaust device that performs degassing from the raised wafer, a low-temperature cryopanel is provided between the wafer dehydrating chamber and the exhaust device, and a reducing or dehydrating or rare gas or a rare gas or the like is provided. The method is characterized in that a mixed gas is inserted into a wafer dehydration processing chamber at a predetermined pressure, and degassing is efficiently performed from a wafer whose temperature has been raised.

[0007] The temperature of the cryopanel is about 70K.
It is preferred that

Further, the predetermined pressure is from 10 ^-3 Torr to
It is preferably 10 ^-1 Torr.

Further, it is preferable that after performing degassing with a reducing or dehydrating property or a mixed gas thereof, degassing is performed with a rare gas to replace the gas.

Preferably, the temperature of the wafer is set to be 100 ° C. or higher.

Further, it is preferable to use a turbo pump as an exhaust device and to further improve exhaust characteristics by combining the turbo pump and a cryopanel.

[0012]

Next, an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic diagram showing the configuration of an embodiment of the degassing system of the present invention. This figure shows a degassing pretreatment system in a sputtering apparatus as one embodiment of the present invention. The wafer 5 having an interlayer film is sent to a pre-processing chamber via a load lock. At this time, the pre-processing chamber is a wafer dehydration processing chamber 6 having a chamber configuration having a gate valve with a small capacity. The chamber 6 has a holder capable of raising the substrate temperature to about 500 ° C., a turbo pump 2 as an exhaust device, and a cryopanel 1 arranged at an inlet of the turbo pump 2. The temperature of the cryopanel 1 is kept at about 70K. The shield 3 around the holder increases conductance and improves exhaust characteristics. The gas injected into the chamber 6 can be a reducing gas, a dehydrating gas, a rare gas, or a mixed gas thereof. Now, the substrate temperature is set to 300 ° C., and Ar gas containing 2% of dry chlorine flows into the chamber 6 so that the gas pressure becomes about 20 mTorr. Moisture adsorbed on the substrate and moisture in the film are efficiently removed by flowing a gas containing a trace amount of chlorine having a substrate temperature and a dehydrating effect. The moisture desorbed into the chamber 6 is adsorbed by the cryopanel 1 before entering the turbo pump 2, so that a small amount of gas from the turbo pump 2 does not return. Because the cryopanel 1 is kept at 70K,
Since only the hydrates of water and chlorine are adsorbed and Ar, which is a rare gas having a low boiling point, is not adsorbed, the efficiency of removing water becomes effective.

Next, the operation of the embodiment of the present invention will be described in detail with reference to FIG. A reducing gas, a dehydrating gas, or a rare gas, or a mixed gas thereof is caused to flow at a gas pressure higher than normal of several tens of mTorr, and the evacuation capacity is increased by the turbo pump 2. To make it easier. At this time, since the temperature of the wafer 5 is at least 100 ° C. or more, the evaporation of moisture is facilitated. Further, since the cryopanel 1 is provided at the entrance of the turbo pump 2, the desorbed moisture and reducing By adsorbing the hydrate or the like in which the gas and the water have reacted, the gas flows back and can be degassed effectively without re-adhering.

As described above, according to the present invention, in the pretreatment chamber in the sputtering apparatus, the wafer 5 is set on the stage whose stage temperature is set so that the wafer temperature on the stage is 100 ° C. or more and the process temperature + 25 ° C. or less.
Is inserted at a gas pressure of 10 ^-3 Torr or more and 10 ^-1 Torr or less, and the wafer 5 is heated to oxidize the wafer 5. Degassing in the film can be performed efficiently.

[0016]

As described above, according to the present invention,
Since the gas to be inserted is reducing and dehydrating, and the gas pressure is higher than usual, the separated gas is easily exhausted, and oxides at the bottom such as holes are easily reduced. Therefore, degassing time can be reduced by effectively performing degassing for a long time,
The oxide at the bottom of the hole can be easily removed, and the yield of via holes and the like is improved.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a configuration of an embodiment of the present invention.

FIG. 2 is a schematic view showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cryopanel 2 Exhaust device (turbo pump) 3 Shield 4 Gas inlet 5 Wafer 6 Chamber 12 Exhaust device (cryopump)

Claims (6)

[Claims] 1. A degassing method comprising a holder for raising the temperature of a wafer in a wafer dehydration processing chamber used for manufacturing a semiconductor device, and an exhaust device for degassing from the wafer with an increased temperature. Between the wafer dehydration processing chamber and the exhaust device,
A low-temperature cryopanel is provided, and a reducing or dehydrating or rare gas or a mixed gas thereof is inserted into the wafer dehydration processing chamber at a predetermined pressure, and degassing is efficiently performed from a wafer whose temperature has been raised. Degassing method. 2. The degassing method according to claim 1, wherein the temperature of the cryopanel is about 70K. 3. The method according to claim 1, wherein the predetermined pressure is 10 ^-3 Torr to 10 Torr.
^-1 Torr.
Degassing method described in 1. 4. The method according to claim 1, wherein after performing degassing with said reducing or dehydrating or mixed gas thereof, degassing is performed with a rare gas to replace the gas. The degassing method according to any one of the above. 5. The degassing method according to claim 1, wherein the temperature of the wafer is set to be 100 ° C. or higher. 6. A turbo pump is used as said exhaust device,
The degassing method according to any one of claims 1 to 5, wherein the exhaust characteristics are further improved by combining the turbo pump and the cryopanel.