Methods of forming a low resistance silicon-metal contact
View Patent ↗A method of forming an ohmic contact on a substrate is described. The method includes depositing a set of silicon particles on the substrate surface. The method also includes heating the substrate in a baking ambient to a baking temperature and for a baking time period in order to create a densified film ink pattern. The method further includes exposing the substrate to a dopant source in a diffusion furnace with a deposition ambient, the deposition ambient comprising POCl 3 , a carrier N 2 gas, a main N 2 gas, and a reactive O 2 gas at a deposition temperature and for a deposition time period, wherein a PSG layer is formed on the substrate surface. The method also includes heating the substrate in a drive-in ambient to a drive-in temperature and for a drive-in time period; and depositing a silicon nitride layer. The method further includes depositing a set of metal contacts on the set of silicon particles; and heating the substrate to a firing temperature and for a firing time period.
1. A method of forming an ohmic contact on a substrate, comprising:
depositing a set of silicon particles on the substrate surface, wherein the set of silicon particles comprises one of phosphorous-doped silicon particles and intrinsic silicon particles;
heating the substrate in a baking ambient to a baking temperature and for a baking time period in order to create a densified film ink pattern;
exposing the substrate to a dopant source in a diffusion furnace with a deposition ambient, the deposition ambient comprising POCl 3 , a carrier N 2 gas, a main N 2 gas, and a reactive O 2 gas at a deposition temperature and for a deposition time period, wherein a PSG layer is formed on the substrate surface;
heating the substrate in a drive-in ambient to a drive-in temperature and for a drive-in time period;
depositing a silicon nitride layer;
depositing a set of metal contacts on the set of silicon particles;
heating the substrate to a firing temperature and for a firing time period.
2. The method of claim 1 , wherein the baking temperature is between about 150° C. and about 600° C. and the baking time period is between about 30 seconds and about 10 minutes.
3. The method of claim 1 ,wherein a ratio of the carrier N 2 gas to the reactive O 2 gas is between about 1:1 to about 1.5:1, the deposition temperature is between about 725° C. and about 875° C., and the deposition time period of about 5 minutes and about 35 minutes.
4. The method of claim 1 , wherein the drive-in temperature is between about 800° C. and about 1000° C.
5. The method of claim 1 , wherein the baking temperature is between about 200° C. and about 400° C. and the baking time period is between about 30 seconds and about 2 minutes.
6. The method of claim 1 , wherein the deposition temperature is between about 750° C. and about 850° C., and the deposition time period is between about 10 minutes and about 30 minutes.
7. The method of claim 1 , wherein the drive-in temperature is between about 850° C. and about 1000° C.
8. The method of claim 1 , wherein the drive-in temperature is between about 850° C. and about 900° C.
9. The method of claim 1 , wherein the drive-in time period is between about 15 minutes and about 40 minutes.
10. The method of claim 1 , wherein the maximum firing temperature is between about 700° C. and about 800° C. and the firing time period is between about 1 second and about 5 seconds.
11. The method of claim 1 , wherein the firing temperature is between about 750° C. and about 780° C. and the firing time period is between about 3 seconds and about 4 seconds.
12. The method of claim 1 , wherein the PSG is removed after heating the substrate in a drive-in ambient to a drive-in temperature and for a drive-in time period.
13. The method of claim 1 , wherein the substrate is cleaned after heating the substrate in a baking ambient to a baking temperature and for a baking time period.
14. A method of forming an ohmic contact on a substrate, comprising:
(A) exposing the substrate to a dopant source in a diffusion furnace with a deposition ambient, the deposition ambient comprising POCl 3 , a carrier N 2 gas, a main N 2 gas, and a reactive O 2 gas at a deposition temperature and for a deposition time period, wherein a PSG layer is formed on the substrate surface;
(B) heating the substrate following said exposing (A) in a drive-in ambient to a drive-in temperature and for a drive-in time period;
(C) depositing a set of silicon particles on the substrate surface following said heating (B);
(D) heating the substrate following said depositing (C) in a baking ambient to a baking temperature and for a baking time period in order to create a densified film ink pattern;
(E) depositing silicon nitride layer following said heating (D);
(F) depositing a set of metal contacts on the set of silicon particles following said depositing (E); and
(G) heating the substrate to a firing temperature and for a firing time period following said depositing (F).
15. The method of 14 , wherein the set of silicon particles includes greater than 1 at % phosphorous.
16. The method of claim 14 , wherein the baking temperature is between about 150° C. and about 600° C., and the baking time period is between about 30 seconds and about 10 minutes.
17. The method of claim 14 , wherein the baking temperature is between about 200° C. and about 400° C. and the baking time period is between about 30 seconds and about 2 minutes.
18. The method of claim 14 , wherein the PSG is removed after heating the substrate in a drive-in ambient to a drive-in temperature and for a drive-in time period.
19. The method of claim 14 , wherein the substrate is cleaned after heating the substrate in a baking ambient to a baking temperature and for a baking time period.
20. A method of forming an ohmic contact on a substrate, comprising:
(A) exposing the substrate to a dopant source in a diffusion furnace with a deposition ambient, the deposition ambient comprising POCl 3 , a carrier N 2 gas, a main N 2 gas, and a reactive O 2 gas at a deposition temperature and for a deposition time period, wherein a PSG layer is formed on the substrate surface;
(B) heating the substrate following said exposing (A) in a drive-in ambient to a drive-in temperature and for a drive-in time period;
(C) depositing silicon nitride layer following said heating (A);
(D) depositing a set of silicon particles on the substrate surface following said depositing (C);
(E) heating the substrate following said depositing (D) in a baking ambient to a baking temperature and for a baking time period in order to create a densified film ink pattern;
(F) depositing a set of metal contacts on the set of silicon particles following said heating (E); and
(G) heating the substrate to a firing temperature and for a firing time period following said depositing (F).
21. The method of 20 , wherein the set of silicon particles includes greater than 1 at % phosphorous.
22. The method of claim 20 , wherein the baking temperature is between about 150° C. and about 600° C. and the baking time period is between about 30 seconds and about 10 minutes.
23. The method of claim 20 , wherein the baking temperature is between about 200° C. and about 400° C. and the baking time period is between about 30 seconds and about 2 minutes.
24. The method of claim 20 , wherein the substrate is cleaned after heating the substrate in a baking ambient to a baking temperature and for a baking time period.