Photo-assisted CVD

• US 4,435,445 A
• Filed: 05/13/1982
• Issued: 03/06/1984
• Est. Priority Date: 05/13/1982
• Status: Expired due to Term

• Current Assignee: Atlantic Richfield Company Incorporated (BP PLC)
• Original Assignee: Energy Conversion Devices
• Inventors: Ovshinsky, Stanford R., Walter, Lee, Reyes, Jaime M., Allred, David D.
• Primary Examiner(s): Newsome, John H.
• Application Number:
  US06/377,738
• Time in Patent Office: 663 Days
• Field of Search: 427/54.1, 427/53.1, 427/252, 427/86, 204/157.1 R, 204/152.1 H
• US Class Current: 427/583
• CPC Class Codes: C23C 16/047 using irradiation by energy or particles
• CPC Class Codes: C23C 16/482 using incoherent light, UV to IR, e.g. lamps
• CPC Class Codes: C23C 16/488 Protection of windows for introduction of radiation into the coating chamber

Abstract

A process and apparatus for depositing a film from a gas involves introducing the gas to a deposition environment containing a substrate, heating the substrate, and irradiating the gas with radiation having a preselected energy spectrum, such that a film is deposited onto the substrate. In a preferred embodiment, the energy spectrum of the radiation is below or approximately equal to that required to photochemically decompose the gas. In another embodiment, the gas is irradiated through a transparent member exposed at a first surface thereof to the deposition environment, and a flow of substantially inert gaseous material is passed along the first surface to minimize deposition thereon.

Claims

1. A process for making an amorphous silicon and germanium alloy film comprising:

providing a gas comprising silane and germane in a deposition environment containing the substrate;

heating the substrate below the temperature required for pyrolysis of the silane and germane;

irradiating the silane and germane with radiation below an energy level required to photochemically decompose the gas; and

the combination of heat and radiation causing deposition of an amorphous silicon and germanium alloy film on the substrate.

2. The process of claim 1 wherein the substrate is heated to a temperature of at least about 250°

C.

3. The process of claim 1 wherein the radiation is ultraviolet light.

4. The process of claim 3 wherein the ultraviolet light has a wavelength of greater than 2,000 Å

.

5. The process of claim 1 wherein the radiation is passed through a transparent member exposed at a first surface thereof to the deposition environment, and the process further comprises establishing a flow of substantially inert gaseous material along the first surface to minimize deposition thereon.

6. The process of claim 5 wherein the step of establishing the flow comprises producing a laminar gas curtain along the first surface.

7. The process of claim 1 wherein the gas in the deposition environment consists essentially of silane and germane.