Etch Difficulty Index; A Measure of Difficulty of Etching of a Surface Film in Presence of Complex Tall Structure Patterns Used in Advance CMOS Technologies
Original Publication Date: 2003-Jun-27
Included in the Prior Art Database: 2003-Jun-27
A concept of Etch Difficulty Index (EDI) has been defined as a relative means of estimating the difficulty in wet etch process, based only on geometric design parameters of a given part number. Calculation of this index uses the design parameters like chip length, chip width, C4 pitch, actual number of C4's on the chip, and the width of widest kerf. EDI number, independent of wafer size, is calculated as a dimensionless index. This index provides a quick method of comparing a new product with the existing ones to the designer in estimating the level of etch challenge that a new product can present.