Apparatus and method for forming polycrystalline silicon thin film

• US 20070054499A1
• Filed: 08/31/2006
• Published: 03/08/2007
• Est. Priority Date: 09/06/2005
• Status: Active Grant

• Current Assignee: Wonik IPS Co., Ltd.
• Original Assignee: Tera Semicon Corporation
• Inventors: Lee, Young, Jang, Taek, Lee, Byoung
• Granted Patent: US 7,439,116 B2
• Time in Patent Office: Days
• US Class Current: 438/778
• CPC Class Codes: C23C 16/18 from metallo-organic compounds
• CPC Class Codes: C23C 16/24 Deposition of silicon only
• CPC Class Codes: C23C 16/45525 Atomic layer deposition [ALD]
• CPC Class Codes: C23C 16/45555 applied in non-semiconductor technology
• CPC Class Codes: C23C 16/56 After-treatment
• CPC Class Codes: H01L 21/02422 Non-crystalline insulating materials, e.g. glass, polymers
• CPC Class Codes: H01L 21/02532 Silicon, silicon germanium, germanium
• CPC Class Codes: H01L 21/02672 using crystallisation enhancing elements
• CPC Class Codes: Y10T 117/1016 with means for treating single-crystal [e.g., heat treating]

Abstract

Apparatus and method for forming a polycrystalline silicon thin film by converting an amorphous silicon thin film into the polycrystalline silicon thin film using a metal are provided. The method includes: a metal nucleus adsorbing step of introducing a vapor phase metal compound into a process space where the glass substrate having the amorphous silicon formed thereon is disposed, to adsorb a metal nucleus contained in the metal compound into the amorphous silicon layer; a metal nucleus distribution region-forming step of forming a community region including a plurality of silicon particles every metal nucleus in a plane boundary region occupied by the metal compound by a self-limited mechanism due to the adsorption of the metal nucleus; and an excess gas removing step of purging and removing an excess gas which is not adsorbed in the metal nucleus distribution region-forming step.

Claims

1. A method for forming a polycrystalline silicon thin film by including depositing an amorphous silicon layer on a glass substrate and forming a metal layer on the amorphous silicon layer to crystallize the amorphous silicon layer, the method comprising:

a metal nucleus adsorbing step of introducing a vapor phase metal compound into a process space where the glass substrate having the amorphous silicon formed thereon is disposed, to adsorb a metal nucleus contained in the metal compound into the amorphous silicon layer;

a metal nucleus distribution region-forming step of forming a community region including a plurality of silicon particles every metal nucleus in a plane boundary region occupied by the metal compound by a self-limited mechanism due to the adsorption of the metal nucleus; and

an excess gas-removing step of purging and removing an excess gas which is not adsorbed in the metal nucleus distribution region-forming step.

2. The method according to claim 1, after removing the excess gas in the excess gas removing step, further comprising a metal nucleus disposition density adjusting step of thermally treating and oxidizing the metal nucleus in an oxygen ambient to randomly suppress a metal-silicide nucleus formation for a metal-induced crystallization and performing a metal-induced crystallization process.

3. The method according to claim 1, after removing the excess gas in the excess gas removing step, further comprising a distribution density adjusting step of reacting the amorphous silicon layer with radicals other than the adsorbed metal nucleus by a thermal decomposition or by introducing a reaction gas, purging and removing the remaining radicals to release the community region, again adsorbing the metal compound between the occupied metal nuclei to adjust the distribution density of the metal nuclei.

4. The method according to claim 1, after removing the excess gas in the excess gas removing step, further comprising a polycrystallinelization processing step of performing a thermal treatment for a crystallization in a reaction chamber that is the same process space.

5. The method according to claim 1, wherein a metal constituting the vapor phase metal compound is any one selected from the group consisting of Ni, Al, Ti, Ag, Au, Co, Sb, Pd, Cu, or a combination thereof.

6. The method according to claim 1, wherein the metal nucleus distribution region-forming step is performed using an ALD (atomic layer deposition).

7. The method according to claim 6, wherein after the metal nucleus distribution region-forming step, the excess gas removing step comprises reacting the amorphous silicon layer with radicals other than the adsorbed metal nucleus by a thermal decomposition or by introducing a reaction gas, and purging and removing the remaining radicals such that the metal nuclei are distributed at a single atomic layer thickness or less by the ALD of one cycle.

8. The method according to claim 1, wherein the metal nucleus adsorbing-step is performed in a temperature environment having a temperature range of 100-300°

C.

9. The method according to claim 1, wherein the vapor phase metal compound is supplied with a pressure of 0.1 Torr to 300 Torr.

10. The method according to claim 2, wherein the oxygen ambient of the metal nucleus disposition density adjusting step is formed by introducing O₂ gas, H₂O gas, N₂O gas or O₃ gas into the process space.

11. The method according to claim 2, wherein the oxygen ambient is formed by introducing oxygen compound into the process space in a plasma state.

12. The method according to claim 2, wherein the thermal treatment in the metal nucleus disposition density adjusting step is performed in a temperature range of from a metal nucleus adsorbing process temperature to a crystallization heat treatment temperature.

13. The method according to claim 2, wherein the heat treatment in the metal nucleus disposition density adjusting step is included in a temperature elevation process for performing a metal-induced crystallization.

14. The method according to claim 2, wherein the metal nucleus disposition density adjusting step further comprises a grain size adjusting step of adjusting the grain size depending on the temperature of the heat treatment and an exposure time.

15. The method according to claim 1, after removing the excess gas in the excess gas removing step, further comprising:

a metal nucleus disposing step of reacting the amorphous silicon layer with radicals other than the adsorbed metal nucleus by a thermal decomposition or by introducing a reaction gas, and purging and removing the remaining radicals to dispose only the metal nucleus; and

a metal catalyst-containing amorphous silicon layer-forming step of forming an amorphous silicon layer having a remainder thickness on a distribution of the metal nuclei disposed on the amorphous silicon layer formed at a predetermined thickness in the metal nucleus-disposing step.

16. In an apparatus for forming a polycrystalline silicon thin film including an amorphous silicon deposition apparatus having a first reaction chamber that is a process space, for depositing an amorphous silicon layer on a glass substrate is installed, and a metal nucleus deposition apparatus having a second reaction chamber that is a separate process space from the deposition apparatus, for depositing a metal nucleus on the glass substrate having the amorphous silicon layer formed thereon, the apparatus for forming a polycrystalline silicon thin film comprising:

a source gas supply unit (10) for supplying a vapor phase metal compound for an adsorption of a metal nucleus into a reaction chamber providing a process space, together with a deposition gas supplying unit (12) for deposition of an amorphous silicon layer;

a gas exhaust unit (14) for exhausting the reacted deposition gas and an excess gas; and

a heating unit (16) disposed in the reaction chamber (1) to provide the reaction chamber with a thermal decomposition temperature environment for the deposition of the amorphous silicon layer and a thermal treatment environment for adsorption of the metal nucleus,

wherein the reaction chamber (1) is included in the apparatus for forming a polycrystalline silicon thin film, as an in-situ process reaction chamber for performing a step of depositing the amorphous silicon layer and a step of adsorbing the metal nucleus in a same process space in-situ using the source gas supply unit (10), the gas exhaust unit (14) and the heating unit (16).

17. In an apparatus for forming a polycrystalline silicon thin film including a metal nucleus deposition apparatus having a first reaction chamber that is a process space, for depositing a metal nucleus on a glass substrate having an amorphous silicon layer formed thereon, and a crystallization process apparatus having a second reaction chamber that is a separate process space from the metal nucleus deposition apparatus, for thermally treating the glass substrate with the metal nucleus to perform a crystallization of the amorphous silicon layer, the apparatus for forming a polycrystalline silicon thin film comprising:

a source gas supply unit (10) for supplying a vapor phase metal compound for an adsorption of a metal nucleus into a reaction chamber providing a process space;

a gas exhaust unit (14) for exhausting an excess gas; and

a heating unit (16) disposed in the reaction chamber (1) to provide the reaction chamber with a thermal decomposition temperature environment for the adsorption of the metal nucleus and a thermal treatment environment for crystallization of the amorphous silicon layer,

wherein the reaction chamber (1) is included in the apparatus for forming a polycrystalline silicon thin film, as an in-situ process reaction chamber for performing a step of adsorbing the metal nucleus on the glass substrate and a thermal treatment step in a same process space in-situ using the source gas supply unit (10), the gas exhaust unit (14) and the heating unit (16).

18. In an apparatus for forming a polycrystalline silicon thin film including a metal nucleus deposition apparatus having a first reaction chamber that is a process space, for depositing a metal nucleus on a glass substrate having an amorphous silicon layer formed thereon, and a crystallization process apparatus having a second reaction chamber that is a separate process space from the metal nucleus deposition apparatus, for thermally treating the glass substrate with the metal nucleus to perform a crystallization of the amorphous silicon layer, the apparatus for forming a polycrystalline silicon thin film comprising:

a source gas supply unit (10) for supplying a vapor phase metal compound for an adsorption of a metal nucleus into a distribution process reaction chamber providing a process space;

a gas exhaust unit (14) for exhausting an excess gas;

a heating unit (16) provided for an adsorption of a metal nucleus;

a crystallization process reaction chamber (18) separately disposed from the distribution process reaction chamber (1) and provided with the heating unit (16);

wherein the crystallization process reaction chamber (18) is connected with the distribution process reaction chamber through a loadlock room (20) having an end effector (22) for loading/unloading the glass substrate such that the glass substrate (100) transferred from the distribution process reaction chamber (1) is thermally treated.