Plasma state monitoring to control etching processes and across-wafer uniformity, and system for performing same

• US 7,402,257 B1
• Filed: 07/30/2002
• Issued: 07/22/2008
• Est. Priority Date: 07/30/2002
• Status: Active Grant

• Current Assignee: Advanced Micro Devices, Inc.
• Original Assignee: Advanced Micro Devices, Inc.
• Inventors: Sonderman, Thomas J., Markle, Richard J.
• Primary Examiner(s): OLSEN, ALLAN W
• Application Number:
  US10/209,585
• Time in Patent Office: 2,184 Days
• Field of Search: 216/60, 216/61, 216/67, 700/1, 700 28- 33, 700/121, 700/266, 700/303, 438/5, 438/9, 438/10
• US Class Current: 216/60
• CPC Class Codes: H01L 22/20 Sequence of activities consisting of a plurality of measurements, corrections, marking or sorting steps

Abstract

The present invention is generally directed to plasma state monitoring to control etching processes and across-wafer uniformity, and a system for performing same. In one illustrative embodiment, the method comprises generating a plasma within an etching tool, monitoring at least one characteristic of the generated plasma, and controlling at least one parameter of a plasma etching process performed in the tool based upon the monitored at least one characteristic of the plasma. In another illustrative embodiment, the method comprises generating a plasma within an etch tool, performing a plasma etching process within the etch tool, determining at least one characteristic of the plasma, and controlling at least one parameter of the etching process based upon a comparison of the determined at least one characteristic of the plasma and a target value for the determined at least one characteristic of the plasma.

Claims

1. A method, comprising:

generating a plasma within an etching tool having at least one wafer disposed therein;

monitoring at least one characteristic of said generated plasma, said at least one characteristic being indicative of at least one physical aspect of at least one feature formed on the wafer; and

controlling at least one parameter of a plasma etching process performed in said tool based upon said monitored at least one characteristic of said plasma, wherein controlling at least one parameter of a plasma etching process performed in said tool based upon said monitored at least one characteristic of said plasma comprises controlling at least one parameter of an anisotropic plasma etching process performed in said tool based upon said monitored at least one characteristic of said plasma.

2. A method, comprising:

generating a plasma within an etching tool having at least one wafer disposed therein;

monitoring at least one characteristic of said generated plasma, said at least one characteristic being indicative of at least one physical aspect of at least one feature formed on the wafer; and

controlling at least one parameter of a plasma etching process performed in said tool based upon said monitored at least one characteristic of said plasma, wherein controlling at least one parameter of a plasma etching process performed in said tool based upon said monitored at least one characteristic of said plasma comprises controlling at least one parameter of an isotropic plasma etching process performed in said tool based upon said monitored at least one characteristic of said plasma.

3. A method comprising:

generating a plasma within an etching tool having at least one wafer disposed therein;

monitoring at least one characteristic of said generated plasma, said at least one characteristic being indicative of at least one physical aspect of at least one feature formed on the wafer; and

controlling at least one parameter of a plasma etching process performed in said tool based upon said monitored at least one characteristic of said plasma, wherein controlling at least one parameter of a plasma etching process performed in said tool based upon said monitored at least one characteristic of said plasma comprises controlling at least one parameter of a plasma etching process performed in said tool based upon said monitored at least one characteristic of said plasma such that said plasma etch process exhibits a desired across-wafer etch pattern wherein said desired across-wafer etch pattern is an etch pattern, and wherein said plasma etch process etches at a faster rate at an edge region of a wafer as compared to the etch rate of the process at a center region of a wafer.

4. A method, comprising:

generating a plasma within an etching tool having at least one wafer disposed therein;

monitoring at least one characteristic of said generated plasma, said at least one characteristic being indicative of at least one physical aspect of at least one feature formed on the wafer; and

controlling at least one parameter of a plasma etching process performed in said tool based upon said monitored at least one characteristic of said plasma, wherein controlling at least one parameter of a plasma etching process performed in said tool based upon said monitored at least one characteristic of said plasma comprises controlling at least one parameter of a plasma etching process performed in said tool based upon said monitored at least one characteristic of said plasma such that said plasma etch process exhibits a desired across-wafer etch pattern wherein said desired across-wafer etch pattern is an etch pattern and wherein said desired across-wafer etch pattern is an etch pattern wherein said plasma etch process etches at a slower rate at an edge region of a wafer as compared to the etch rate of the process at a center region of a wafer.

5. A method, comprising:

generating a plasma within an etch tool having at lest one wafer disposed therein;

performing a plasma etching process within said etch tool;

determining at least one characteristic of said plasma, said at least one characteristic being indicative of at least one physical aspect of at least one feature formed on the wafer; and

controlling at least one parameter of said etching process based upon a comparison of said determined at least one characteristic of said plasma and a target value for said determined at least one characteristic of said plasma, wherein controlling at least one parameter of a plasma etching process performed in said tool based upon said monitored at least one characteristic of said plasma comprises controlling at least one parameter of a plasma etching process performed in said tool based upon said monitored at least one characteristic of said plasma such that said plasma etch process exhibits a desired across-wafer etch pattern and wherein said desired across-wafer etch pattern is an etch pattern wherein said plasma etch process etches at a faster rate at an edge region of a wafer as compared to the etch rate of the process at a center region of a wafer.

6. A method, comprising:

generating a plasma within an etch tool having at lest one wafer disposed therein;

performing a plasma etching process within said etch tool;

determining at least one characteristic of said plasma, said at least one characteristic being indicative of at least one physical aspect of at least one feature formed on the wafer; and

controlling at least one parameter of said etching process based upon a comparison of said determined at least one characteristic of said plasma and a target value for said determined at least one characteristic of said plasma, wherein controlling at least one parameter of a plasma etching process performed in said tool based upon said monitored at least one characteristic of said plasma comprises controlling at least one parameter of a plasma etching process performed in said tool based upon said monitored at least one characteristic of said plasma such that said plasma etch process exhibits a desired across-wafer etch pattern and wherein said desired across-wafer etch pattern is an etch pattern wherein said plasma etch process etches at a slower rate at an edge region of a wafer as compared to the etch rate of the process at a center region of a wafer.

7. A method comprising:

generating a plasma within an etch tool;

performing a plasma etching process within said etch tool to define at least one feature in or above a semiconducting substrate;

determining a metric for said plasma, said metric being based upon at least one characteristic of said plasma; and

controlling at least one parameter of said etching process based upon a comparison of said determined metric and a target metric for said plasma, said target metric being associated with at least one of a target profile, a target critical dimension a target depth, a target height, and a target thickness for said at least one feature, wherein controlling at least one parameter of said etching process based upon said determined metric and said target metric for said plasma comprises controlling at least one parameter of said etching process such that said plasma etch process exhibits a desired across-wafer etch pattern, and wherein said desired across-wafer etch pattern is an etch pattern wherein said plasma etch process exhibits varying etch rates across a surface of said wafer.

8. A method, comprising:

generating a plasma within an etch tool;

performing a plasma etching process within said etch tool to define at least one feature in or above a semiconducting substrate;

determining a metric for said plasma, said metric being based upon at least one characteristic of said plasma; and

controlling at least one parameter of said etching process based upon a comparison of said determined metric and a target metric for said plasma, said target metric being associated with at least one of a target profile, a target critical dimension, a target depth, a target height, and a target thickness for said at least one feature, wherein controlling at least one parameter of said etching process based upon said determined metric and said target metric for said plasma comprises controlling at least one parameter of said etching process such that said plasma etch process exhibits a desired across-wafer etch pattern, and wherein said desired across-wafer etch pattern is an etch pattern wherein said plasma etch process etches at a faster rate at an edge region of a wafer as compared to the etch rate of the process at a center region of a wafer.

9. A method, comprising:

generating a plasma within an etch tool;

performing a plasma etching process within said etch tool to define at least one feature in or above a semiconducting substrate;

determining a metric for said plasma, said metric being based upon at least one characteristic of said plasma; and

controlling at least one parameter of said etching process based upon a comparison of said determined metric and a target metric for said plasma, said target metric being associated with at least one of a target profile, a target critical dimension, a target depth, a target height and a target thickness for said at least one feature, wherein controlling at least one parameter of said etching process based upon said determined metric and said target metric for said plasma comprises controlling at least one parameter of said etching process such that said plasma etch process exhibits a desired across-wafer etch pattern, and wherein said desired across-wafer etch pattern is an etch pattern wherein said plasma etch process etches at a slower rate at an edge region of a wafer as compared to the etch rate of the process at a center region of a wafer.