High density plasma deposition and etching apparatus

• US 4,990,229 A
• Filed: 06/13/1989
• Issued: 02/05/1991
• Est. Priority Date: 06/13/1989
• Status: Expired due to Term

• Current Assignee: SPTS Technologies Limited (KLA Corporation)
• Original Assignee: Plasma & Materials Technologies, Inc.
• Inventors: Shoji, Tatsuo, Conn, Robert W., Campbell, Gregor
• Primary Examiner(s): Weisstuch, Aaron
• Application Number:
  US07/365,533
• Time in Patent Office: 602 Days
• Field of Search: 204/192.12, 204/192.32, 204/298 ME, 204/298 EE, 204/298.16, 204/298.37, 204/298.06, 204/298.07, 204/298.34, 204/298.33 , 204/298.18, 204/298.19, 156/345, 156/643, 118/723, 42/39, 315/111.41, 422/186.05
• US Class Current: 204/298.06
• CPC Class Codes: H01J 37/321 the radio frequency energy being inductively coupled to the plasma
• CPC Class Codes: H01J 37/3211 Antennas, e.g. particular shapes of coils
• CPC Class Codes: H01J 37/3266 Magnetic control means
• CPC Class Codes: H01J 37/32688 Multi-cusp fields

Abstract

The high density RF plasma generator of this invention uses special antenna configurations (15) to launch RF waves at low frequency such as 13.56 MHz along a magnetic field supplied by an external magnetic field generator (16.17) in a discharge space (14) where the working gas is introduced and which is used alone or in conjunction with a process chamber (18) where specimen substrates (20) are located to either deposit or etch films from a substrate or to sputter deposit films to a substrate. The plasma etching, deposition and/or sputtering system comprises the high density RF plasma generator, the external magnetic field, the gas injection and control system, the antenna system (15) and associated power supplies (48), the process chamber (18), and the means to couple plasma from the generator to substrates or targets, including magnetic means (36) to enhance plasma uniformity at the substrates (20) or targets (92).

Claims

1. A plasma processing apparatus, comprising:

(a) an antenna, the antenna radiating electromagnetic waves, the antenna comprising;

(i) a first current loop, the first current loop residing in a first plane and;

(ii) a second current loop, the second current loop residing in a second plane, the first and second current loops residing in a spaced apart relationship wherein the first plane and the second plane are substantially parallel;

(b) a plasma generation chamber, the plasma generation chamber being proximate to and in electromagnetic communication with the antenna, such that a line perpendicular to the planes of the first and second current loops defines a longitudinal axis of the plasma generation chamber;

(c) a first fluid injector, the first fluid injector introducing a fluid into the plasma generation chamber, thereby permitting the creation of a plasma within the plasma generation chamber;

(d) a magnetic field generator, the magnetic field generator generating a magnetic field;

(e) a process chamber, the plasma being transported to the process chamber by the magnetic field;

(f) a second fluid injector, the second fluid injector introducing a fluid into the process chamber.

(g) a current controller, the current controller controlling the current within the magnetic field generator, thereby controlling plasma shape;

(h) a substrate holder, the substrate holder residing within the process chamber;

(i) an auxiliary radio frequency generator, the auxiliary radio frequency generator adapted for applying radio frequency power to a substrate residing on the substrate holder;

(j) a radio frequency exciter, the radio frequency exciter generating a radio frequency voltage and current; and

(k) a matching network, the matching network interconnecting the radio frequency exciter and the antenna, thereby promoting the efficient transfer of radio frequency energy from the radio frequency exciter to the antenna.

2. The plasma processing apparatus of claim 1, wherein the generated magnetic field is parallel to the longitudinal axis of the plasma generation chamber.

3. The plasma processing apparatus of claim 2, wherein the substrate holder is supported within the process chamber in a state of substantial electrical insulation.

4. The plasma processing apparatus of claim 3, wherein the substrate holder comprises:

(a) A copper block;

(b) Thermal control means, permitting temperature regulation of the copper block.

5. The plasma processing apparatus of claim 4, wherein the second fluid injector is formed as a porous element, thereby permitting a gas to be introduced within the element, the gas escaping from the element into the process chamber.

6. The plasma processing apparatus of claim 5, wherein the porous element is formed as a ring, the ring being constructed of tubing, the tubing being perforated so as to permit the gas to escape from the ring into the process chamber.

7. The plasma processing apparatus of claim 6, wherein the plasma generation chamber is a quartz cylinder.

8. The plasma processing apparatus of claim 1, further comprising a plurality of magnets, the magnets being arranged in a circumferential manner proximate to the process chamber, succeeding magnets having opposite orientations of north and south poles.

9. The plasma processing apparatus of claim 8, wherein the process chamber has a cross sectional area that is larger than a cross section of the plasma generation chamber.

10. The plasma processing apparatus of claim 9, wherein the process chamber is formed substantially of stainless steel.

11. The plasma process apparatus of claim 10, wherein the cross section of the process chamber is a regular geometric shape.

12. A sputter deposition device according to claim 9, further comprising

(a) at least one target;

(b) biasing means, the biasing means applying a voltage to the target, thereby causing ions with the plasma to bombard the target and causing material from the target to be deposited on the substrate.

13. The sputter deposition device of claim 12, wherein the target is a magnetron sputter target.

14. The sputter deposition device of claim 12, wherein the substrate holder is formed as an aperture, thereby permitting the plasma to travel past the substrate holder enroute to the target, the plasma thereby bombarding the target and sputtering material onto the substrate.

15. The plasma processing apparatus of claim 8, further comprising:

(a) a plurality of plasma generation chambers, each plasma generation chamber being cooperatively connected to the processing chamber;

(b) a plurality of antennas, each antenna being electromagnetically coupled to a plasma generation chamber; and

(c) a plurality of magnetic field generators, each magnetic field generator being magnetically coupled to each plasma generation chamber.

16. The plasma processing apparatus of claim 1, further comprising

(a) a plurality of plasma generation chambers, each plasma generation chamber being cooperatively connected to the process chamber, each plasma generation chamber being coaxial to the longitudinal axis of the plasma generation chamber;

(b) a plurality of antennas, each antenna being electromagnetically coupled to a plasma generation chamber;

(c) a plurality of magnetic field coils, the magnetic field coil being proximate to the process chamber;

(d) a plurality of magnetic field generators, each magnetic field generator being magnetically coupled to each plasma generator; and

(d) a plurality of substrate holders mounted within the process chamber.

17. A sputter deposition device according to claim 1, further comprising:

(a) First magnetic field coils, the first magnetic field coils being magnetically coupled and proximate to the plasma generation chamber, the first magnetic field coils generating a magnetic field in a first direction;

(b) Second magnetic field coils, the second magnetic field coils being magnetically coupled and proximate to the process chamber, the second magnetic field coils generating a magnetic field in a second direction, the second direction being substantially parallel to the first direction;

(c) Third magnetic field coils, the third magnetic field coils being magnetically coupled and proximate to a target, the target residing within the process chamber, the magnetic field coils causing the plasma to conform to the target; and

(d) A negative voltage power supply, the negative voltage power supply being electrically coupled to the target, the target thereby depositing material onto the substrate.

18. A sputter deposition device according to claim 17, further comprising a baffle, the baffle residing within the process chamber, the baffle permitting control of fluid injection into the process chamber.