Directional etching of Si with perfect selectivity to SiO2 using an ultraclean electron cyclotron resonance plasma

Abstract

Using a newly developed ultraclean electron cyclotron resonance plasma etcher, Si wafers masked by SiO2 were etched with a chlorine plasma at pressures of 0.6–4.0 mTorr with a microwave power of 300–700 W. Ultraclean processing under a low ion energy condition at high pressures has revealed that there is an induction period during which time there is no SiO2 etching. This is not observed with Si. During the induction period, perfectly selective etching for Si to SiO2 has been achieved. Under this perfectly selective condition, anisotropic tenth micron patterns of polycrystalline silicon have been obtained with little undercut.

Reactive ion etching of silicon stencil masks in the presence of an axial magnetic field

“…The etch rates obtained in the axial-field RIE system are comparable to those reported in other systems for the etching of sub-0.5 m structures. 7,20 Structures presented in this article have better sidewall profiles than any reported in the literature so far. Hence, it can be concluded that Si etching in a molecular bromine plasma using a novel axial-field RIE system is the best process available for the fabrication of ion masks, particularly for sub-0.1 m resolution.…”

Progress and prospects in nanoscale dry processes: How can we control atomic layer reactions?

“…[38][39][40][41][42][43] Matsuura and coworkers demonstrated the atomic layer-bylayer etching of silicon-related materials. [44][45][46][47] Many of these prior investigations were summarized by Kanarik et al to show the compound effort and progress in atomic layer etching in the semiconductor industry. 14) A very important merit of plasma processing is that it enables the deposition and etching of materials with high quality at low temperatures through the use of energetic species present within the discharge.…”

Characterization of SiO2 Etching Profiles in Pulse-Modulated Capacitively Coupled Plasmas

“…As the feature size of semiconductors continues to decrease, and the structure of semiconductors is altered from two to three dimensions, high-aspect-ratio contact (HARC) hole etching has emerged as one of the most important goals in the semiconductor manufacturing process. Achieving high-performance HARC hole etching requires high selectivity [1][2][3][4][5][6][7], anisotropic etching [8][9][10][11][12], and reduced charge damage [13][14][15][16]. As continuous wave (CW) plasma reacts with a consistent ion flux on a wafer surface, it is difficult to attain these aspects with CW plasma.…”