Method of planarizing microstructures

• US 5,419,803 A
• Filed: 11/17/1993
• Issued: 05/30/1995
• Est. Priority Date: 11/17/1993
• Status: Expired due to Term

• Current Assignee: Integrated Process Equipment Corp. (Speedfam Co., Ltd)
• Original Assignee: Hughes Aircraft Company (Rtx Corporation)
• Inventors: Mumola, Peter B.
• Primary Examiner(s): POWELL, WILLIAM A
• Application Number:
  US08/153,681
• Time in Patent Office: 559 Days
• Field of Search: 156/636, 156/643, 156/657, 156/626, 204/192.37, 204/192.33, 437/228, 356/355
• US Class Current: 216/38
• CPC Class Codes: H01L 21/31053 involving a dielectric removal step

Abstract

A method of planarizing a microstructure (16) includes the steps of providing a layer (18) of material over the microstructure (16) such that an overcoating surface (20) is formed, measuring the thickness of the layer (18) across the surface (20) forming a dwell time versus position map and removing material from the layer (18) of material by use of a plasma assisted chemical etching tool in accordance with the dwell time versus position map.

Claims

1. A method of planarizing a microstructure having a plurality of features extending from a surface thereof, said method comprising the steps of:

providing a layer of material over said microstructure such that an overcoating surface is formed;

measuring the thickness of said layer across the surface thereof;

forming a dwell time versus position map for said surface; and

removing material from said layer of material by use of a plasma assisted chemical etching tool, said material removal being in accordance with said dwell time versus position map.

2. The method as claimed in claim 1 wherein said layer providing step is carried out until all of said features are overcoated.

3. The method as claimed in claim 1 wherein said layer providing step includes the step of depositing material on said microstructure to establish said layer of material over said microstructure.

4. The method as claimed in claim 3 wherein said layer providing step includes forming said layer to a minimum thickness of about one to five micrometers.

5. The method as claimed in claim 1 wherein said measuring step includes the step of computing the thickness of a plurality of points of said surface.

6. The method as claimed in claim 1 wherein said measuring step includes the step of computing the thickness of said plurality of points on a point-by-point basis.

7. The method as claimed in claim 6 wherein said measuring step includes the step of computing the thickness of said surface by use of a full surface imaging spectral reflectometer.

8. The method as claimed in claim 1 wherein said layer providing step includes depositing a material that is transparent to said full surface interferometer.

9. The method as claimed in claim 1 wherein said material removal step includes removing material from said layer so that a minimum of between zero and 0.05 micrometers remains over a feature that is greatest in height above said surface of said microstructure.