Apparatus for forming silicon oxide film and method of forming silicon oxide film

• US 6,239,044 B1
• Filed: 05/28/1999
• Issued: 05/29/2001
• Est. Priority Date: 06/08/1998
• Status: Expired due to Fees

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Suzuki, Toshihiko, Kataoka, Toyotaka, Kashiwagi, Akihide
• Primary Examiner(s): Nelms, David
• Assistant Examiner(s): Dang, Phuc T.
• Application Number:
  US09/322,020
• Time in Patent Office: 732 Days
• Field of Search: 438/240, 438/758, 438/787, 438/624, 438/773, 438/774, 438/789, 216/59, 216/67, 216/69, 134/1, 134/2, 134/18, 134/22
• US Class Current: 438/787
• CPC Class Codes: C23C 8/02 Pretreatment of the material to be coated C23C8/04 takes precedence
• CPC Class Codes: C23C 8/16 using oxygen-containing compounds, e.g. water, carbon dioxide
• CPC Class Codes: C30B 29/06 Silicon
• CPC Class Codes: C30B 33/005 Oxydation
• CPC Class Codes: H01L 21/02164 the material being a silicon oxide, e.g. SiO2
• CPC Class Codes: H01L 21/02238 silicon in uncombined form, i.e. pure silicon
• CPC Class Codes: H01L 21/02255 formation by thermal treatment H01L21/02252 takes precedence; after treatment of an insulating film H01L21/3105 and subgroups
• CPC Class Codes: H01L 21/31612 on a silicon body

Abstract

An apparatus for forming a silicon oxide film which has a process chamber and is for thermally oxidizing a surface of a silicon layer by introducing water vapor into the process chamber, and which further has dew-formation prevention/evaporation means for preventing dew formation in the process chamber and/or evaporating dew in the process chamber.

Claims

1. A method of forming a silicon oxide film, which comprises the step of:

thermally oxidizing a surface of a silicon layer of a substrate in a process chamber of an apparatus by introducing water into the process chamber;

preventing dew formation in the process chamber, and evaporating any dew previously existing in the process chamber using a dew prevention/evaporation means;

replacing an atmosphere in the process chamber with inert gas in a state where no water vapor is formed in the process chamber; and

transferring the substrate out of the process chamber.

2. The method of claim 1, wherein the apparatus further has:

(a) a water vapor generating apparatus,

(b) a water vapor inlet port disposed in an upper portion of the process chamber, for introducing water vapor into the process chamber, for introducing water vapor into the process chamber,

(c) a gas exhaust portion disposed in lower portion of the process chamber, for exhausting gas from the process chamber,

(d) a substrate transfer portion disposed below the process chamber and allowed to be communicated with the process,

(e) a substrate receiving unit composed of a substrate receiving member for receiving a plurality of substrates having silicon layers, and heat insulation member disposed on the bottom of the substrate receiving member.

(f) an elevator unit for elevating the substrate receiving unit upwardly and downwardly to transfer the substrate receiving unit from the substrate transfer portion to the process chamber and form the process chamber to the substrate transfer portion, and

(g) a heater unit disposed outside the process chamber for heating the silicon layer,

wherein the dew-formation prevention/evaporation means is for preventing dew formation on the surface of the heat insulation member and evaporating dew on the surface of the heat insulation member.

3. The method of claim 2, wherein a surface temperature of the heat insulation member is controlled in a range from 100°

C. to 150°

C. by the dew-formation prevention/evaporation means.

4. The method of claim 2, wherein the dew-formation prevention/evaporation means comprises an inert gas source, an inert gas inlet port disposed in the process chamber, a piping connecting the inert gas inlet portion and the inert gas source, and heating means for heating the inert gas to be introduced into the process chamber.

5. The method of claim 4, wherein the inert gas inlet portion is arranged in the process chamber to allow flow of the inert gas introduced into the process chamber to collide with the heat insulation member.

6. The method of claim 4, wherein the dew-formation prevention/evaporation means further comprises means for measuring a moisture content of the gas exhausted from the gas exhaust portion, and

after the moisture content of the gas exhausted from the gas exhaust portion comes to be equal at most a predetermined value, the substrates are transferred out of the process chamber.

7. The method of claim 2, wherein the dew-formation prevention/evaporation means comprises an auxiliary heating unit which is disposed outside the process chamber and heats the heat insulation member.

8. The method of claim 7, wherein the dew-formation prevention/evaporation means further comprises temperature detecting means for detecting a surface temperature of the heat insulation member and a control unit for controlling the auxiliary heating unit.

9. The method of claim 8, wherein the auxiliary heating unit is a heater.

10. The method of claim 8, wherein the auxiliary heating unit comprises a piping and a hot medium flowing in the piping.

11. The method of claim 1, wherein the water vapor to be introduced into the process chamber is generated by one of the following steps (A) reacting hydrogen gas and oxygen gas at a high temperature, (B) heating pure water, (C) bubbling hot pure water with oxygen gas or inert gas, (D) reacting hydrogen gas and oxygen gas in the presence of a catalyst, or (E) a reaction between oxygen plasma and hydrogen plasma.

12. The method of claim 1, wherein the surface of the silicon layer is thermally oxidized in the process chamber, then, the atmosphere in the process chamber is replaced with inert gas in a state where no dew is formed in the process chamber and/or dew in the process chamber is evaporated, to remove water vapor out of the process chamber, then, an inert gas atmosphere containing halogen element is provided in the process chamber to heat-treat the formed silicon oxide film, and then, the substrate is transferred out of the process chamber.

13. The method of claim 1, wherein the substrate transferred out of the apparatus for forming a silicon oxide film is transferred into a heat treatment apparatus and an inert gas atmosphere containing halogen element is provided in the heat treatment apparatus to heat-treat a formed silicon oxide film.

14. A method of forming a silicon oxide film, which comprises the steps of:

transferring a substrate having a silicon layer into a process chamber;

introducing water vapor into the process chamber to thermally oxidize a surface of the silicon layer;

replacing an atmosphere in the process chamber with an inert gas atmosphere to remove the water vapor and/or dew out of the process chambers; and

transferring the substrate out of the process chamber.

15. The method of claim 14, wherein an ambient temperature of the process chamber for the thermal oxidation of the surface of the silicon layer and an ambient temperature of the process chamber during the removal of the water vapor and/or dew out of the process chamber are nearly equal to each other.

16. The method of claim 15, wherein the ambient temperature of the process chamber for the thermal oxidation of the surface of the silicon layer is 750°

C. or lower.

17. The method of claim 14, wherein the inert gas exhausted out of the process chamber is measured for a moisture content when the water vapor and/or dew are removed out of the process chamber, and after the moisture content of the inert gas exhausted out of the process chamber comes to be equal to, or lower than, a predetermined value, the substrate is transferred out of the process chamber.

18. The method of claim 17, wherein the predetermined value is 0.02 kg per kilogram of dry inert gas.

19. The method of claim 14, wherein the water vapor and/or dew in the process chamber are removed out of the process chamber, then, an inert gas atmosphere containing halogen element is provided in the process chamber to heat-treat the formed silicon oxide film, and then the substrate is transferred out of the process chamber.

20. The method of claim 14, wherein the substrate transferred out of the process chamber is transferred into a heat treatment apparatus, and an inert gas atmosphere containing halogen element is provided in the heat treatment apparatus to heat-treat the formed silicon oxide film.

21. A method of forming a silicon oxide film using apparatus having a process chamber and drw-formation prevention/evaporation means, comprising the steps of:

transferring a substrate having a silicon layer into the process chamber;

introducing water vapor into the process chamber to thermally oxidize a surface of the silicon layer;

thermally oxidizing the surface of the silicon layer in the process chamber;

replacing an atmosphere in the process chamber with inert gas in a state such that no water vapor is formed in the process chamber; and

all drw in the process chamber is evaporated;

preventing drew formation in the process chamber;

evaporating dew formation in the process chamber;

removing water vapor out of the process chamber; and

transferring the substrate out of the process chamber.