A Low-Temperature Atomic Layer Deposition Liftoff Method for Microelectronic and Nanoelectronic Applications

TL;DR

This paper introduces a low-temperature atomic layer deposition liftoff method for creating high-quality patterned dielectric films with sub-micron features, suitable for microelectronic and nanoelectronic applications.

Contribution

It presents a novel low-temperature ALD liftoff technique that achieves sharp edges and high-quality dielectric films with improved conformality and minimal feature size.

Findings

Films exhibit low edge roughness (~10 nm).

Dielectric constants measured: Al2O3 ~8-9, HfO2 ~16-19, ZrO2 ~20-29.

Method enables uniform film growth without resist outgassing.

Abstract

We report a novel method for depositing patterned dielectric layers with sub-micron features using atomic layer deposition (ALD). The patterned films are superior to sputtered or evaporated films in continuity, smoothness, conformality, and minimum feature size. Films were deposited at 100-150C using several different precursors and patterned using either PMMA or photoresist. The low deposition temperature permits uniform film growth without significant outgassing or hardbaking of resist layers. A liftoff technique presented here gives sharp step edges with edge roughness as low as ~10 nm. We also measure dielectric constants (k) and breakdown fields for the high-k materials aluminum oxide (k ~ 8-9), hafnium oxide (k ~ 16-19) and zirconium oxide (k ~ 20-29), grown under similar low temperature conditions.