Laser assisted plasma chemical etching method
First Claim
Patent Images
1. A method for removing material from a semiconductor substrate to thin and smooth said semiconductor substrate, comprising the steps of:
- measuring uniformity of thickness of said semiconductor substrate;
generating a heating profile map from the uniformity of thickness measurement;
placing the semiconductor substrate in an etching chamber;
differentially heating localized portions of said semiconductor substrate in accordance with said heating profile map so that thicker localized portions are at a higher temperature and thinner localized portions of said semiconductor substrate are at a lower temperature; and
etching an entire surface of said semiconductor substrate, wherein the localized portions of said semiconductor substrate that are at a higher temperature are etched at a faster rate than the localized portions of said semiconductor substrate that are at a lower temperature.
7 Assignments
0 Petitions
Accused Products
Abstract
A scaleable laser and control unit (58) is used to differentially heat portions of a semiconductor substrate (40) during downstream etching. Such differential heating provides a differential etch rate for each portion heated resulting in improved uniformity and reduced etch induced surface damage. An etching chamber (50) capable of containing the downstream plasma and providing a direct line of sight between the substrate (40) and the scanable laser unit (58) is provided. In addition, the system provides for dynamic updating of the process by in situ etch rate and temperature measurements.
-
Citations
16 Claims
-
1. A method for removing material from a semiconductor substrate to thin and smooth said semiconductor substrate, comprising the steps of:
-
measuring uniformity of thickness of said semiconductor substrate; generating a heating profile map from the uniformity of thickness measurement; placing the semiconductor substrate in an etching chamber; differentially heating localized portions of said semiconductor substrate in accordance with said heating profile map so that thicker localized portions are at a higher temperature and thinner localized portions of said semiconductor substrate are at a lower temperature; and etching an entire surface of said semiconductor substrate, wherein the localized portions of said semiconductor substrate that are at a higher temperature are etched at a faster rate than the localized portions of said semiconductor substrate that are at a lower temperature. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
-
-
13. A method for producing thin, uniform device wafers, comprising the steps of:
-
providing a wafer substrate in an etching chamber, wherein said wafer substrate further comprises a handle wafer bonded to a device wafer having a major surface; measuring an initial thickness of said device wafer at a plurality of portions of said major surface; heating thicker portions of said major surface to a higher temperature than thinner portions of said major surface; etching the entire major surface of said device wafer wherein an etch rate of a thicker portion of said major surface will be higher than an etch rate of a thinner portion of said major surface; measuring a subsequent thickness of said device wafer at a plurality of portions; calculating an etch rate for said plurality of portions; calculating a heating profile map wherein said heating profile map is determined by thickness and etch rate data for said plurality of portions; heating said plurality of portions to a temperature determined by heating profile map; and repeating the etching, measuring, calculating and heating steps until said device wafer is a predetermined thickness. - View Dependent Claims (14, 15, 16)
-
Specification