Shaping features in sputter deposition

• US 20040140196A1
• Filed: 01/17/2003
• Published: 07/22/2004
• Est. Priority Date: 01/17/2003
• Status: Abandoned Application

• Current Assignee: Applied Materials Incorporated
• Original Assignee: Applied Materials Incorporated
• Inventors: Fu, Jianming, Tang, Xianmin, Gopalraja, Praburam, Chen, Fusen
• Application Number:
  US10/346,974
• Publication Number:
  US 20040140196A1
• Time in Patent Office: Days
• US Class Current: 204/192.12
• CPC Class Codes: C23C 14/046 Coating cavities or hollow spaces, e.g. interior of tubes; Infiltration of porous substrates
• CPC Class Codes: C23C 14/3492 Variation of parameters during sputtering
• CPC Class Codes: C23C 14/35 by application of a magnetic field, e.g. magnetron sputtering C23C14/3457 takes precedence
• CPC Class Codes: C23C 14/54 Controlling or regulating the coating process
• CPC Class Codes: H01L 21/2855 by physical means, e.g. sputtering, evaporation H01L21/28518 - H01L21/28537 and H01L21/28568 take precedence
• CPC Class Codes: H01L 21/76805 the opening being a via or contact hole penetrating the underlying conductor
• CPC Class Codes: H01L 21/76844 Bottomless liners
• CPC Class Codes: H01L 21/76865 Selective removal of parts of the layer H01L21/76844 takes precedence
• CPC Class Codes: H01L 21/76873 for electroplating
• CPC Class Codes: H01L 21/76877 Filling of holes, grooves or trenches, e.g. vias, with conductive material
• CPC Class Codes: H01L 2221/1089 Stacks of seed layers
• CPC Class Codes: H01L 23/53238 Additional layers associated with copper layers, e.g. adhesion, barrier, cladding layers
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00

Abstract

A sputter deposition method is performed in a sputtering chamber having a sputtering target facing a substrate support. A substrate is placed on the support in the chamber and, in a first sputtering stage, a first layer of sputtered material is deposited on the substrate by maintaining a first pressure of a sputtering gas in the chamber, and maintaining the substrate support at a first bias power level. In a second sputtering stage, a second layer of sputtered material is deposited on the substrate by maintaining a second pressure of the sputtering gas that is lower than the first pressure, and maintaining the substrate support at a second bias power level that is higher than the first bias power level.

Claims

1. A sputter deposition method performed in a sputtering chamber comprising a sputtering target facing a substrate support, the method comprising:

(a) placing a substrate on the support in the chamber;

(b) in a first sputtering stage, depositing a first layer of sputtered material on the substrate by;

(i) maintaining a first pressure of a sputtering gas in the chamber, and

(ii) maintaining the substrate support at a first bias power level; and

(c) in a second sputtering stage, depositing a second layer of sputtered material on the substrate by;

(i) maintaining a second pressure of the sputtering gas is that is lower than the first pressure, and

(ii) maintaining the substrate support at a second bias power level that is higher than the first bias power level.

2. A method according to claim 1 wherein the first pressure is at least about 3 mTorr and the-second pressure is less than about 2 mTorr

3. A method according to claim 1 wherein the first support bias power level is less than about 200 Watts and the second support bias power level is at least about 200 Watts.

4. A method according to claim 1 wherein the sputtered material comprises at least one of copper, aluminum, tantalum and titanium.

5. A method according to claim 1 further comprising:

(d) in a third sputtering stage, maintaining a third pressure of the sputtering gas of from about 3 mTorr to about 10 mTorr and maintaining a third bias power level of from about 0 Watts to about 200 Watts.

6. A sputter deposition method performed in a sputtering chamber comprising a sputtering target facing a substrate support, the method comprising:

(a) placing a substrate on the support in the chamber, the substrate comprising a first layer overlying a second layer, the first layer comprising a feature having a bottom wall and sloped sidewalls;

(b) in a first sputtering stage, maintaining first sputtering process conditions to deposit sputtered material on the sloped sidewalls of the feature, thereby protecting the sloped sidewalls, the first sputtering process conditions comprising;

(i) maintaining a pressure of a sputtering gas in the chamber of from about 3 mTorr to about 10 mTorr, and

(ii) maintaining the substrate support at a first bias power level of from about 0 Watts to about 200 Watts; and

(c) in a second sputtering stage, maintaining second sputtering process conditions to sputter the bottom wall of the feature to expose a portion of the second layer, the second sputtering process conditions comprising;

(i) maintaining a pressure of the sputtering gas in the chamber of from about 0 mTorr to about 2 mTorr; and

(ii) maintaining the substrate support at a second bias power level that is higher than the first bias power level, the second bias power level being from about 200 Watts to about 800 Watts.

7. A method according to claim 6 further comprising:

in a third sputtering stage, maintaining third sputtering process conditions to deposit sputtered material on the exposed portion of the second layer, the third sputtering process conditions comprising maintaining a pressure of the sputtering gas in the chamber of from about 3 mTorr to about 10 mTorr, and maintaining the substrate support at a bias power level of from about 0 Watts to about 200 Watts.

8. A sputter deposition method performed in a sputtering chamber comprising a sputtering target comprising copper facing a substrate support, the method comprising:

(a) placing a substrate on the support in the chamber, the substrate comprising a barrier layer over an underlying layer of copper, wherein the barrier layer comprises a feature formed therein, the feature having a bottom wall and sloped sidewalls;

(b) in a first sputtering stage, maintaining first sputtering process conditions to deposit copper sputtered from the target onto the sloped sidewalls of the feature, thereby protecting the sloped sidewalls, the first sputtering process conditions comprising;

(i) maintaining a pressure of a sputtering gas comprising Ar in the chamber of from about 3 mTorr to about 10 mTorr, and

(ii) maintaining the substrate support at a first bias power level of from about 0 Watts to about 200 Watts; and

(c) in a second sputtering stage, maintaining second sputtering process conditions to sputter the bottom wall of the feature to expose a portion of the underlying copper layer, the second sputtering process conditions comprising;

(i) maintaining a pressure of the sputtering gas in the chamber of from about 0 mTorr to about 2 mTorr; and

(ii) maintaining the substrate support at a second bias power level that is higher than the first bias power level, the second bias power level being from about 200 Watts to about 800 Watts; and

(d) in a third sputtering stage, maintaining third sputtering process conditions to deposit copper sputtered from the target onto the sidewalls of the feature and onto the exposed portion of the underlying copper layer, the third sputtering process conditions comprising;

(i) maintaining a pressure of the sputtering gas in the chamber of from about 3 mTorr to about 10 mTorr; and

(ii) maintaining the substrate support at a third bias power that is less than the second bias power level, the third bias power level being from about 0 Watts to about 200 Watts.

9. A sputtering chamber for sputter depositing material on a substrate, the chamber comprising:

a substrate support;

a target facing the substrate support;

a sputtering gas delivery system to provide a sputtering gas in the chamber;

a gas energizer to energize the sputtering gas by applying bias power levels to the target and the substrate support, thereby sputtering material from the target onto the substrate;

an exhaust comprising a throttle valve to control a pressure of the sputtering gas in the chamber; and

a controller comprising a computer having computer readable program code embodied in a computer readable medium, the computer readable program code comprising;

(i) gas energizer control instruction sets to operate the gas energizer to;

(1) during a first sputtering stage, apply a first bias power level to the support; and

(2) during a second sputtering stage performed after the first sputtering stage, apply a second bias power level to the support that is higher than the first bias power level; and

(ii) gas pressure control instruction sets to operate the throttle valve to;

(1) during the first sputtering stage, maintain a first pressure of sputtering gas in the chamber; and

(2) during the second sputtering stage, maintain a second pressure of the sputtering gas that is lower than the first pressure.

10. An apparatus according to claim 9 wherein the gas pressure control instruction sets operate the throttle valve to provide a first pressure of from about 0 mTorr to about 2 mTorr, and a second pressure of from about 3 mTorr to about 10 mTorr.

11. A method according to claim 9 wherein the gas energizer control instruction sets operate the gas energizer to apply a first bias power level to the support of from about 0 Watts to about 200 Watts, and a second bias power level to the support of from about 200 Watts to about 800 Watts.

12. A method according to claim 9 wherein the gas pressure control instruction sets operate the throttle valve to provide a third pressure of the sputtering gas in the chamber of from about 3 mTorr to about 10 mTorr in a third sputtering stage performed after the second sputtering stage, and wherein the gas energizer control instruction sets operate the gas energizer to apply a third bias power level to the support during the third sputtering stage that is lower than the second bias power level, the third bias power level being from about 0 Watts to about 200 Watts.