Ald Apparatus and Method

• US 20070269983A1
• Filed: 06/28/2004
• Published: 11/22/2007
• Est. Priority Date: 06/27/2003
• Status: Active Grant

• Current Assignee: Sundew Technologies LLC
• Original Assignee: Ofer Sneh
• Inventors: Sneh, Ofer
• Granted Patent: US 7,662,233 B2
• Time in Patent Office: Days
• US Class Current: 438/689
• CPC Class Codes: C23C 16/4409 characterised by sealing means
• CPC Class Codes: C23C 16/4488 by in situ generation of reactive gas by chemical or electrochemical reaction
• CPC Class Codes: C23C 16/45544 characterized by the apparatus
• CPC Class Codes: C23C 16/45557 Pulsed pressure or control pressure
• CPC Class Codes: C30B 25/14 Feed and outlet means for the gases; Modifying the flow of the reactive gases
• CPC Class Codes: Y10T 117/1004 with means for measuring, testing, or sensing

Abstract

Improved apparatus and method for SMFD ALD include a method designed to enhance chemical utilization as well as an apparatus that implements lower conductance out of SMFD-ALD process chamber while maintaining full compatibility with standard wafer transport. Improved SMFD source apparatuses (700, 700′, 700″) and methods from volatile and non-volatile liquid and solid precursors are disclosed, e.g., a method for substantially controlling the vapor pressure of a chemical source (722) within a source space comprising: sensing the accumulation of the chemical on a sensing surface (711); and controlling the temperature of the chemical source depending on said sensed accumulation.

Claims

1. A chemical source vapor pressure control system (700) comprising a deposition chamber (708), a chemical source holder (722) for holding said chemical source, a chemical source heater (720), a source heater controller (728), and a deposition accumulation sensor (710), said heater controller electrically connected to said deposition accumulation sensor to control the heating of said source;

said system characterized by;

said temperature controlled deposition accumulation sensor (710) located out of line-of sight with said chemical source; and

a sensor temperature control unit (712) for controlling the temperature of said accumulation sensor to a temperature lower than the condensation temperature of the chemical source at the desired vapor pressure.

2. A chemical source control system as in claim 1 wherein said deposition chamber has chamber walls (708) and further comprising a chamber wall temperature control system for maintaining said walls at a temperature that is sufficiently high to prevent condensation of said chemical source.

3. The chemical source vapor pressure control system as in claim 1 and further characterized by a pressure gauge (706), a gas control valve (744), and a pressure controller (752) connected between said gauge and said valve to control the total pressure within said deposition chamber to a pressure higher than said controlled vapor pressure of said chemical source.

4. The chemical source vapor pressure control system as in claim 1 and further characterized by a source of an etch gas connected to said gas control valve, and said sensor senses an etching product.

5. The chemical source vapor pressure control system as in claim 4 and characterized in that said chemical source is selected from the group consisting of Hf, Zr, Ru, RuO₂, Si, W, Mo, Co, Cu, Al, Os, OsO₂, Fe, Ta and combinations thereof;

and said etching gas is selected from the group consisting of of Cl₂, Cl₂/N₂, Cl₂/O₂/O₃, N₂/HF, N₂/ClF₃, CO, CO/N₂ and combinations thereof.

6. The chemical source vapor pressure control system as in claim 1 and further characterized by a pressure controlled reservoir (780);

a shutoff valve (744′

) in series fluidic communication between said pressure controlled reservoir and said deposition chamber to substantially equalize the pressure between said deposition chamber and said pressure controlled reservoir between successive ALD doses.

7. The chemical source vapor pressure control system as in claim 1 wherein said source is applied for ALD and the capacity of said deposition chamber is 20 times or more larger than the capacity required for a single ALD dose.

8. A method for substantially controlling the vapor pressure of a chemical source within a source space said method comprising:

sensing the accumulation of said chemical on a sensing surface; and

controlling the temperature of said chemical source depending on said sensed accumulation.

9. A method as in claim 8 wherein said temperature of said chemical source is controlled to maintain a minimal measurable condensation rate on said sensing surface.

10. The method of claim 8 and further characterized by controlling the temperature of said sensor to appropriately determine the desired vapor pressure of said chemical.

11. The method of claim 8 and further characterized by controlling the total pressure in said source space to be higher than said vapor pressure of said chemical.

12. The method of claim 8 and further characterized by introducing an etching gas into said source space;

and etching an elemental or compound target to produce said chemical.