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US 6,649,528 B2Granted
Local dry etching method
AssigneeSpeedfam Corporation
InventorsMichihiko Yanagisawa, Tadayoshi Okuya
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Abstract
In a local dry etching method of the invention, a surface of a representative wafer sampled from a lot is test etched, each wafer of which is sliced from the same ingot, and initial data of recesses and projections of which is previously known, recesses and projections of the representative wafer is measured after test etched, an etching profile is derived from the initial data and measured data and then respective wafer surfaces of the lot are etched in condition calculated by using at least the derived etching profile.
Claims2
A local dry etching method, comprising:
- test etching a surface of a representative wafer sampled from a lot, each wafer of said lot being sliced from a same ingot;
- measuring recesses and projections of said surface of the representative wafer after said test etching, initial data of recesses and projections of said surface of the representative wafer that is not subjected to the test etching being known;
- deriving an etching profile from said initial data and measured data;
- and
- etching surfaces of the wafers of said lot in a condition calculated by using at least said etching profile,
- wherein the test etching comprises injecting a gas of an activated species from a nozzle stationary above one point of said surface of the representative wafer for a predetermined period of time;
- and
- the measuring recesses and projections provides data of recesses and projections along a line passing through at least said one point.
5 more elements
Dependencies are inferred from the claim text.