Rotary silicon wafer cleaning apparatus

• US 7,103,990 B2
• Filed: 09/11/2003
• Issued: 09/12/2006
• Est. Priority Date: 09/24/2002
• Status: Expired due to Fees

• Current Assignee: Fujikin Incorporated, Pre-Tech Co. Ltd. (Obara Group, Inc.), Tadahiro Ohmi
• Original Assignee: Fujikin Incorporated
• Inventors: Fujita, Takumi, Ohmi, Tadahiro, Morimoto, Akihiro, Ikeda, Nobukazu, Shirai, Yasuyuki, Minami, Yukio, Kawada, Koji
• Primary Examiner(s): GRAVINI, STEPHEN MICHAEL
• Application Number:
  US10/498,800
• Publication Number:
  US 20050126030A1
• Time in Patent Office: 1,097 Days
• Field of Search: 343/25, 343/30, 343/81, 343/80, 34/58, 34/80
• US Class Current: 34/325
• CPC Class Codes: H01L 21/02052 Wet cleaning only H01L21/02085 takes precedence
• CPC Class Codes: H01L 21/67034 for drying

Abstract

It is an object of the present invention to provide a rotation type silicon wafer cleaning device to further raise the stability of a silicon wafer by providing a better hydrogen termination on the silicon wafer after completion of chemical and pure water cleaning treatments.

According to the present invention, a rotation type silicon wafer cleaning device has a silicon wafer support/rotation driving mechanism inside the case body for cleaning the silicon wafer at the post chemical cleaning with pure water, drying and hydrogen termination treatments on the outer surface of a silicon wafer is performed by means of installing a silicon wafer drying device comprising a gas supply panel attached to a case body to supply a mixed gas of the hydrogen gas and inactive gas containing a hydrogen gas of more than 0.05%, a mixed gas supply pipe coupled to a gas mixer of the afore-mentioned gas supply panel at one end, a mixed gas heating device to heat the mixed gas in the afore-mentioned gas supply pipe, and a hydrogen radical formation apparatus equipped with a platinum coating film to form hydrogen radical at the gas contacting part where to a high temperature gas heated with the afore-mentioned mixed gas heating device touches, thus to gush out the mixed gas containing hydrogen radical formed with the afore-mentioned radical formation apparatus onto the rotating silicon wafer after cleaning is completed.

Claims

1. A rotation silicon wafer cleaning device for performing drying and hydrogen termination treatment on an outer surface of a silicon wafer, comprising:

(a) a case body;

(b) a silicon wafer support and rotation driving mechanism disposed inside the case body; and

(c) a silicon wafer drying device including

(i) a gas supply panel having a gas mixer, the supply panel being disposed to supply a mix of hydrogen gas and inert gas, the mix comprising greater than 0.05% by volume of hydrogen;

(ii) a mixed gas supply pipe coupled to the gas mixer;

(iii) a mixed gas heating device disposed to heat the mixed gas in the mixed gas supply pipe; and

(iv) a hydrogen radical formation and dispersion apparatus disposed to receive the heated mixed gas from the mixed gas supply pipe, having a platinum film disposed to form hydrogen radicals in the heated mixed gas, the hydrogen radical formation and dispersion apparatus disposed to direct the mixed gas containing hydrogen radicals onto a rotating silicon wafer.

2. A rotation silicon wafer cleaning device in accordance with claim 1, wherein said mixed gas supply pipe further comprises:

(a) a vertical coupling pipe having an end and disposed to move upward and downward within said case body and further disposed to rotate within said case body; and

(b) a lateral coupling pipe coupled to the end of the vertical coupling pipe and supported horizontally.

3. A rotation silicon wafer cleaning device in accordance with claim 1, wherein said mixed gas heating device comprises a sheathed heater disposed to heat said mixed gas to a temperature higher than 150°

C.

4. A rotation silicon wafer cleaning device in accordance with claim 1, wherein said hydrogen radical formation and dispersion apparatus further comprises a platinum coated filter fitted to said mixed gas supply pipe.

5. A rotation silicon wafer cleaning device in accordance with claim 1, wherein said mix of gas comprises hydrogen in a range of 0.05%–

5.0% by volume.

6. A rotation silicon wafer cleaning device in accordance with claim 2, wherein said vertical coupling pipe comprises:

(a) a coupling pipe body having an inner face, and

(b) a sheathed heater having an outer face and disposed inside the coupling pipe body,

wherein said vertical coupling pipe is disposed to heat said mixed gas as said mixed gas passes between the inner face of the vertical coupling pipe body and the outer face of the sheathed heater.

7. A rotation silicon wafer cleaning device in accordance with claim 2, wherein said lateral coupling pipe comprises:

(a) a stainless steel outer pipe,

(b) an inner pipe having an outer peripheral face and disposed inside the stainless steel outer pipe,

(c) a spacer disposed to permit mixed gas to pass between the stainless steel outer pipe and the inner pipe,

(d) a micro sheathed heater wound around the outer peripheral face of the inner pipe, and

(e) an aluminum foil covering around the micro sheathed heater.

8. A rotation silicon wafer cleaning device in accordance with claim 2, further comprising a lift/rotation driving mechanism disposed to move the vertical coupling pipe between an upper position and a lower position, so that when said vertical coupling pipe is disposed in a lower position, a distance between a lower face of said hydrogen radical formation and dispersion apparatus and an upper face of said silicon wafer becomes between about 0.5 mm–

3 mm.

9. A rotation silicon wafer cleaning device in accordance with claim 3, wherein the temperature of the mixed gas to be supplied to a hydrogen radical formation and dispersion apparatus reaches 150°

C.–

300°

C.

10. A rotation silicon wafer cleaning device in accordance with claim 4, wherein said hydrogen radical formation and dispersion apparatus comprises:

(a) a reverse-dish-shaped upper body having an upper wall, a lower face side, and a mixed gas inlet opening at the center of the upper wall;

(b) a reflecting plate disposed horizontally on the lower face side of the upper body and having a plurality of gas permeating orifices;

(c) a short cylinder-shaped filter flange having a lower face side and welded to the lower face side of the upper body; and

(d) a platinum coated filter comprising a platinum coating on a porous disc made of the stainless-steel-sintered materials, and fixed to the lower face side of the filter flange.

11. A method for performing drying and hydrogen termination treatment on the outer surface of a silicon wafer, comprising the steps of:

(a) providing a mix of hydrogen and inert gas,

(b) heating the mixed gas to a temperature of greater than 150°

C.,

(c) passing the heated mixed gas through a platinum catalyst to generate hydrogen radicals to form a heated gas comprising hydrogen radicals, and

(d) exposing a silicon wafer to the heated gas comprising hydrogen radicals.

12. A method in accordance with claim 11, where said mixed gas is heated to a temperature of 150°

C.–

300°

C.

13. A method in accordance with claim 11, wherein said mix of gas comprises hydrogen in a range of 0.05%–

5.0% by volume.

14. A method for performing drying and hydrogen termination treatment on the outer surface of a silicon wafer, comprising the steps of:

(a) providing a rotation silicon wafer cleaning device, comprising;

(i) a case body;

(ii) a silicon wafer support and rotation driving mechanism disposed inside the case body; and

(iii) a silicon wafer drying device including

(1) a gas supply panel having a gas mixer, the supply panel being disposed to supply a mix of hydrogen gas and inactive gas, the mix comprising greater than 0.05% by volume of hydrogen;

(2) a mixed gas supply pipe coupled to the gas mixer;

(3) a mixed gas heating device disposed to heat the mixed gas in the mixed gas supply pipe; and

(4) a hydrogen radical formation and dispersion apparatus disposed to receive the heated mixed gas from the mixed gas supply pipe, having a platinum film disposed to form hydrogen radicals in the heated mixed gas, the hydrogen radical formation and dispersion apparatus disposed to direct the mixed gas containing hydrogen radicals onto a rotating silicon wafer,

(b) providing a mix of hydrogen and inert gas through said gas supply panel;

(c) heating said mix of gas with said mixed gas heating device;

(d) passing said heated mixed gas through said hydrogen radical formation and dispersion apparatus to form a heated gas comprising hydrogen radicals; and

(e) exposing said silicon wafer to the heated gas comprising hydrogen radicals.

15. A method in accordance with claim 14, wherein during said exposing step (e) said silicon wafer is removably mounted to said wafer support and rotation driving mechanism.

16. The method in accordance with claim 14, wherein during said heating step (c) said mixed gas is heated to a temperature of 150°

C.–

300°

C.

17. A method in accordance with claim 14, wherein said mix of gas comprises hydrogen in a range of 0.05%–

5.0% by volume.