Patent Number: 7,821,142

Title: Intermediate semiconductor device structures

Abstract: An alignment mark mask element protects an underlying alignment mark during subsequent processing of a fabrication substrate. The alignment mark mask element is formed concurrent with formation of a photomask from a dual-tone photoresist that exhibits a pattern reversal upon exposure to an energy level. A portion of the dual-tone photoresist above the alignment mark is exposed to an energy sufficient to reverse a positive tone resist to a negative tone, which remains above the alignment mark after developing. The remainder of the dual-tone photoresist is exposed through a reticle at a lesser energy level and patterned to define aperture locations of a photomask for formation of semiconductor device features. In addition, a photomask for use on a fabrication substrate and an intermediate semiconductor device are disclosed. Methods of forming a photomask and an intermediate semiconductor device structure are also disclosed.

Inventors: Holscher; Richard D. (Boise, ID), Niroomand; Ardavan (Boise, ID)

Assignee: Micron Technology, Inc.

International Classification: H01L 23/544 (20060101)

Expiration Date: 2018-10-26 0:00:00