Chemically Assisted Ion Beam Etching for Silicon‐Based Microfabrication

Abstract

Chemically assisted ion beam etching, using Ar + ions and Cl2 as the reactive gas, has been investigated for the etching of common materials used in silicon-based microfabrication: SiQ, Si3N4, single-crystal St, and polycrystalline St. Two possible etch masks for etching the Si substrate have been characterized: SiO2 and TiW. Etch rates for all these materials and Si etch profiles have been studied as a function of ion energies from 300 to I000 eV, current densities between 0.05 and 0.15 mA/cm ~, and reactive C12 flow rates at substrate temperatures of 30 and 85~ Trenches etched into Si using TiW as a mask showed steeper profiles and less enhanced etching in the bottom corners than those with an SiO2 mask. These etch effects are attributed to a deposited layer on the trench sidewalls, when using TiW as a mask. This Si etch process has important applications in shallow trench isolation for deep submicron complementary metal oxide semiconductor integrated circuits.

Carbon nanotube tipped atomic force microscopy for measurement of <100 nm etch morphology on semiconductors

“…For this study, nanometer-scaled features are fabricated in GaAs-based materials using two different etching techniques, magnetron enhanced reactive ion etching ͑MIE͒ 13 and chemically assisted ion beam etching ͑CAIBE͒. [14][15][16] The morphology of the structures etched using MIE and CAIBE are investigated as a function of etching parameters using AFM with carbon nanotube tips, as well as SEM.…”

Angled etching of Si by ClF3–Ar gas cluster injection

“…20) However, owing to a low mask selectivity and the lateral etching of the sidewall, it is difficult to obtain deep Si etch profiles with high aspect ratios using an ion-beam system. 21) Reactive gas cluster injection is a unique etching method that uses a neutral cluster beam without ions. A gas cluster is an aggregate of 100-50,000 atoms or molecules, and when it bombards a local area, high-density energy deposition and multiple-collision processes occur simultaneously.…”

Oblique-Directional Plasma Etching of Si Using a Faraday Cage

“…5 However, due to a low mask selectivity and the lateral etching of the sidewall, it is difficult to obtain deep Si etch profiles with high aspect ratios using an ion-beam system. 9 Moreover, the multidirectional etching reported by Cheng and Scherer was obtained by performing single-directional etching successively. 5 In this paper, we report on a method for controlling the direction of the Si etch profiles using a Faraday cage and the conventional gas-chopping process.…”