Highly selective etching of LaAlSiO_xto Si using C₄F₈/Ar/H₂plasma

Abstract

Selective etching of LaAlSiOx to Si has been studied in inductively coupled BCl3 plasma using a hot cathode, and in capacitively coupled C4F8/Ar and C4F8/Ar/H2 plasmas. In BCl3 high-temperature etching, the etch selectivity of LaAlSiOx to Si was 0.05 at 210 °C. It was found that increasing the bias power using capacitively coupled C4F8/Ar plasma enhanced LaAlSiOx etching. Furthermore, the etch rate of LaAlSiOx increased and that of Si decreased upon the addition of H2. As a result, a high LaAlSiOx-to-Si selectivity of 6.7 was obtained when using C4F8/Ar/H2 plasma at an H2 flow rate ratio of 13%. We confirmed that H2 played different roles on the LaAlSiOx surface and on the Si surface. H2 suppressed Si etching by forming a high-C/F-ratio polymer on the Si surface, while it enhanced LaAlSiOx etching by breaking the stable metal–oxygen bonds of LaAlSiOx.

Mechanism of SiN etching rate fluctuation in atomic layer etching

“…Atomic layer etching (ALE) is a promising technology that is able to overcome these issues. [1][2][3] ALE has been widely developed in recent years with an emphasis on Si-based, 4 dielectric-based, [5][6][7][8][9][10][11][12][13][14][15] and metal-based [16][17][18][19] materials processing. In this paper, we focus on ALE for dielectric films, which consists of two sequential steps: the surface adsorption of a polymer and desorption steps.…”

Etching of iron and iron–chromium alloys using ICP-RIE chlorine plasma

“…The used RF bias (-150 V ) is higher compared to some ICP etching processes [21,94,95,96,97]. Furthermore, the ion to neutral flux ratio Γ ions /Γ Cl is relatively high (about 38%).…”

Cyclic etching of tin-doped indium oxide using hydrogen-induced modified layer

“…Recently, hydrogen plasma has been employed for difficult-to-etch materials. [10][11][12][13][14][15][16][17][18][19] Hydrogen effectively enhances the etch rates of magnetic materials in a magnetoresistive random access memory (MRAM) stack. 10,20,21) In addition, the self-limited etching of silicon nitride, which is a commonly used dielectric material in conventional semiconductor devices, has also been demonstrated using hydrogen plasma.…”