Plasma enhanced thermal evaporator
View Patent ↗The present invention generally provides a method for forming a photovoltaic device including evaporating a source material to form a large molecule processing gas and flowing the large molecule processing gas through a gas distribution showerhead and into a processing area of a processing chamber having a substrate therein. The method includes generating a small molecule processing gas, and reacting the small molecule processing gas with a film already deposited on a substrate surface to form a semiconductor film. Additionally, apparatuses that may use the methods are also provided to enable continuous inline CIGS type solar cell formation.
1. A method for forming a photovoltaic device, comprising:
evaporating a source material to form a large molecule processing gas;
flowing the large molecule processing gas through a gas distribution showerhead and into a processing area of a processing chamber having a substrate therein;
electrically biasing the gas distribution showerhead to increase energy level of the large molecule processing gas within the processing area without igniting a plasma;
after electrically biasing the gas distribution showerhead, igniting a plasma from the large molecule processing gas, the plasma having a power level;
generating a small molecule processing gas with the plasma; and
reacting the small molecule processing gas with a film already deposited on a substrate surface to form a semiconductor film.
2. The method of claim 1 , wherein the source material comprises selenium.
3. The method of claim 2 , wherein the large molecule processing gas of selenium comprises selenium clusters having five or more selenium atoms.
4. The method of claim 2 , wherein the small molecule processing gas of selenium comprises selenium clusters having four or less selenium atoms.
5. The method of claim 4 , wherein the film already deposited on the substrate surface comprises copper, indium, and gallium.
6. The method of claim 5 , wherein the semiconductor film has a structure represented by the formula CuIn x Ga (1-x) Se 2 where 0<x<1.
7. A method for forming a photovoltaic device, comprising:
evaporating a source material to form a large molecule processing gas;
flowing the large molecule processing gas through a gas distribution showerhead and into a processing area of a processing chamber having a substrate disposed therein;
applying a power level to the gas distribution showerhead to generate a small molecule processing gas from the large molecule processing gas without igniting a plasma; and
reacting the small molecule processing gas with a film already deposited on a substrate surface to form a semiconductor film.
8. The method of claim 7 , wherein the source material comprises selenium.
9. The method of claim 8 , wherein the large molecule processing gas of selenium comprises selenium clusters having five or more selenium atoms.
10. The method of claim 8 , wherein the small molecule processing gas of selenium comprises selenium clusters having four or less selenium atoms.
11. The method of claim 10 , wherein the film already deposited on the substrate surface comprises copper, indium, and gallium.
12. The method of claim 11 , wherein the semiconductor film has a structure represented by the formula CuIn x Ga (1-x) Se 2 where 0<x<1.