Veeco Instruments Inc.

Katrina Rook

Ajit P Paranjpe

Boris L Druz

Timothy Pratt

Narasimhan Srinivasan

Pattern-multiplication via a multiple step ion beam etching process utilizing multiple etching steps. The ion beam is stationary, unidirectional or non-rotational in relation to the surface being etched during the etching steps, but sequential etching steps can utilize an opposite etching direction. Masking elements are used to create additional masking elements, resulting in decreased spacing between adjacent structures and increased structure density.

Ion beam etching

This disclosure provides various methods for improved etching of spin-transfer torque random access memory (STT-RAM) structures. In one example, the method includes (1) ion beam etch of the stack just past the MTJ at near normal incidence, (2) a short clean-up etch at a larger angle in a windowed mode to remove any redeposited material along the sidewall that extends from just below the MTJ to just above the MTJ, (3) deposition of an encapsulant with controlled step coverage to revert to a vertical or slightly re-entrant profile from the tapered profile generated by the etch steps, (4) ion beam etch of the remainder of the stack at near normal incidence while preserving the encapsulation along the sidewall of the MTJ, (5) clean-up etch at a larger angle and windowed mode to remove redeposited materials from the sidewalls, and (6) encapsulation of the etched stack.

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Jericho, NY, United States of America

Katrina Rook