Apparatus for atomic layer chemical vapor deposition

• US 6,812,157 B1
• Filed: 05/20/2002
• Issued: 11/02/2004
• Est. Priority Date: 06/24/1999
• Status: Expired due to Fees

• Current Assignee: Atomic Precision Systems Incorporated
• Original Assignee: Prasad Narhar Gadgil
• Inventors: Gadgil, Prasad Narhar
• Primary Examiner(s): LUND, JEFFRIE ROBERT
• Application Number:
  US10/019,244
• Time in Patent Office: 897 Days
• Field of Search: 118/715, 118/725, 118/728-730, 117/88, 117/98, 117/200, 427/255.7, 438/761-763, 428/543
• US Class Current: 438/763
• CPC Class Codes: C23C 16/45551 for relative movement of the substrate and the gas injectors or half-reaction reactor compartments
• CPC Class Codes: C23C 16/45578 Elongated nozzles, tubes with holes
• CPC Class Codes: C23C 16/45589 Movable means, e.g. fans
• CPC Class Codes: C23C 16/45593 Recirculation of reactive gases
• CPC Class Codes: C23C 16/5096 Flat-bed apparatus
• CPC Class Codes: Y10T 117/10 Apparatus

Abstract

An atomic layer deposition (ALD) reactor (13) is disclosed that includes a substantially cylindrical chamber (15) and a wafer substrate (22) mounted within the chamber (15). The ALD reactor (13) further includes at least one injection tube (14) mounted within the chamber (15) having a plurality of apertures (32) along one side that directs gas emanating from the apertures (32) towards the wafer substrate (22). While gas is pulsed from the injection tube (14), either the water substrate (22) or the injection tube (14) is continuously rotated in a longitudinal plane within the chamber (15) to ensure complete and uniform coverage of the wafer substrate (22) by the gas.

Claims

1. An atomic layer deposition (ALD) reactor, comprising:

a substantially cylindrical chamber;

a substrate mounted within the chamber; and

at least one injection tube mounted within the chamber having a plurality of apertures along one side that direct gas emanating from the apertures towards the substrate, wherein the substrate is covered with a gas deposition sequence comprising a first reactive gas (A), an inert gas (P), the second reactive gas (B), and the inert gas (P),

wherein while gas is pulsed from the injection tube, the substrate is stationery within the chamber and the at least one injector tube is rotated in a longitudinal plane in relation to the substrate to ensure complete and uniform coverage of the substrate by the gas.

2. The ALD reactor of claim 1 wherein the one injection tube comprises a first injection tube, the ALD reactor further including a second injection tube and a third injection tube mounted within the chamber parallel and in close proximity to opposite sides of the first injection tube.

3. The ALD reactor of claim 2 wherein the first injection tube dispenses gas P, the second injection tube dispenses gas A, in the third injection tube dispenses gas B.

4. The ALD reactor of claim 1 wherein the at least one injection tube comprises a cross injector tube configuration.

5. The ALD reactor of claim 1 wherein the at least one injection tube comprises a radial gas injector configuration.

6. A method for depositing an atomic layer of a solid film on a wafer substrate, comprising the steps of:

(a) placing at least one injector tube substantially parallel and in proximity to the substrate, wherein the injector tube includes a plurality of slots for gas flow towards the substrate;

(b) pulsing a first reactive gas through the injector tube to chemically saturated the substrate;

(c) pulsing an inert gas through the injector tube to remove an excess of the first reactive gas, creating a chemisorbed mono-layer of the first-gas;

(d) pulsing a second reactive gas through the injector tube to form one layer of the film;

(e) pulsing the inert gas through the injector tube to remove an excess of the second reactive gas; and

(f) continuously rotating one of the substrate and the at least one injector tube in relation to one another during the pulsing steps, wherein

a time for one complete substrate rotation is denoted by T seconds,

one gas pulse is completed in T/2 seconds, and

a deposition sequence of the first reactive gas, the inert gas, the second reactive gas, and the inert gas is completed in 2T seconds.

7. The method of claim 6 further including the step of fixing the injection tube in place and rotating the substrate in relation thereto.

8. The method of claim 7 further including the steps of:

providing cross-injector tubes for pulsing the gases;

rotating the substrate at least 90 degrees during each of the gas pulses; and

completing a deposition sequence of the first reactive gas, the inert gas, the second reactive gas, and the inert gas in a 360 degree rotation of the substrate.

9. The method of claim 7 further including the steps of:

holding the substrate face-down; and

pulsing the gases upward towards the substrate through the at least one injector tube.

10. The method of claim 6 further including the step of pulsing the gases through longitudinal injector tubes located parallel to the substrate having spaced apertures for directing gas towards the substrate.

11. The method of claim 10 further including the step of rotating the substrate through at least 180 degrees during each of the gas pulses.

12. The method of claim 6 further including the steps of:

holding the substrate stationery; and

rotating the at least one injector tube in relation thereto.

13. An atomic layer deposition (ALD) reactor, comprising:

a substantially cylindrical chamber, the cylindrical chamber having a diagonal;

a rotatable pedestal mounted coaxially within the chamber for holding a wafer substrate, the wafer substrate having a diagonal; and

at least one injection tube mounted within the chamber opposite to the rotatable pedestal and located substantially along the diagonal of the chamber, the injection tube having a plurality of spaced openings facing the rotatable pedestal, such that gas emanating from the openings in the injection tube impinge upon the diagonal of the wafer substrate,

wherein while gas emanates from the injection tube, the rotatable base rotates around its axis at a predefined velocity to coaxially rotate the wafer substrate in a longitudinal plane within the chamber to ensure complete and uniform coverage of the wafer substrate by the gas.

14. The ALD reactor of claim 13 wherein the injection tube has at least one end closed.

15. The ALD reactor of claim 14 further including a gas inlet coupled to the center of the injection tube.

16. The ALD reactor of claim 14 further including a gas inlet coupled to an open end of the injection tube.

17. The ALD reactor of claim 13 wherein the injection tube comprises a first injection tube, the ALD reactor further including a second injection tube, and the third injection tube located parallel and in close proximity to opposite sides of the first injection tube.

18. The ALD reactor of claim 17 wherein the first injection tube is coupled to an inert gas source, the second injection tube is coupled to a first reactive gas source, and the third injection tube is coupled to a second reactive gas source.

19. The ALD reactor of claim 18 wherein the rotatable pedestal includes a heater for supplying heat energy to the wafer substrate to affect a desire chemical reaction.