Test pattern for trench poly over-etched step and formation method thereof
AssigneesCsmc Technologies Fab1 Co., Ltd., Csmc Technologies Fab2 Co., Ltd.
InventorZheng Bian
Life of this patent
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Abstract
A test pattern for testing a trench POLY over-etched step is provided. The test pattern is a trench (14) formed on a substrate (1); the trench (14) comprises a bottom surface and two side surfaces extending from the bottom surface; the trench (14) is formed on the substrate (1) with a preset angle of non-90° formed between the longitudinal direction (L) thereof and the longitudinal direction (X) of a wafer scribing trench. The test pattern can extend the scanning length of a step scanning equipment without changing the width of the trench.
Claims8
A method of fabricating a test pattern for testing a trench POLY over-etched step, comprising:
- forming a trench on a substrate, the trench comprising a bottom surface and two side surfaces extending from the bottom surface, wherein the trench is formed on the substrate with a preset angle, the preset angle being less than or greater than 90°, formed by a longitudinal direction of the trench and a longitudinal direction of a wafer scribe line;
- filling the trench with polysilicon;
- after filling the trench, etching the polysilicon in the trench;
- and
- after etching the polysilicon, testing the trench POLY over-etched step by scanning, by a step scanning equipment, the test pattern along the longitudinal direction of the wafer scribe line and obtaining a depth difference between a surface of the polysilicon and an edge of the trench,
- wherein a width of the trench is in a range of from 0.18 microns to 0.36 microns.
Dependencies are inferred from the claim text.