Method for forming a laser alterable fuse area of a memory cell using an etch stop layer

US5821160A · kind A · utility

Assignee

• Motorola, Inc. · US

Inventors

• Robert Rodriguez · San Jose, US
• Douglas J. Dopp · Hopewell Junction, US
• Robert E. Booth · Austin, US

Key dates

• Filing date: Jun 6, 1996
• Grant date: Oct 13, 1998
• Expiry date: Jun 6, 2016

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10B10/15

Abstract

A method for manufacturing an static random access memory (SRAM) cell (10) begins by manufacturing a fuse region (36) over a substrate (10). An etch stop layer (44) is formed overlying the fuse region (36) from resistor polysilicon material. In order for the fuse region (36) to be accessed and properly disabled, an opening (60) must be provided which stops on the etch stop layer (44). The etch stop (44) ensures a consistent and repeatable optimal thickness X of dielectric material above the fuse region (36) to provide for proper laser access and repair. The etch stop layer (44) therefore reduces wafer to wafer and die to die variation in thickness X and provides for a higher yield laser repair for each SRAM integrated circuit and every wafer processed using this methodology.