Inductively coupled plasma etching of HgCdTe using a CH4-based mixture

Abstract

We report results on a study on inductively coupled plasma (ICP) etching of HgCdTe using a CH 4 -based mixture. Effects of key process parameters on etch rates were investigated and are discussed in this article in light of plasma parameter measurements, performed using a Langmuir probe. Process parameters of interest include ICP source power, substrate power, pressure, and CH 4 concentration. We show that the ICP etching technique allows us to obtain etch rates of about 200 nm/min, which is high enough to use this technique in a manufacturing process. We also observe that the ion bombardment has a strong influence on HgCdTe etch rate. Finally, we show that this etch rate is modified by the substitution of methane for hydrogen.

Effect of High-Density Plasma Process Parameters on Carrier Transport Properties in p-to-n Type Converted Hg0.7Cd0.3Te Layer

“…A number of papers investigating either parallelplate or high-density RIE of HgCdTe have focused on the application of the technology to dry physical etching of high-resolution and high-aspect ratio structures typically required for current state-ofthe-art HgCdTe IR focal plane arrays. 6,7 In these cases, it is desired to control the etch process for controlled anisotropic removal of material, resulting in smooth etched surfaces, high aspect ratios, and minimal modification of the electrical properties of the material. In contrast to the investigation of RIE processing for dry etching applications, the aim of the present study is to identify plasma conditions which favor controlled p-to-n type conversion.…”

Plasma Passivation Etching for HgCdTe

“…[1][2][3][4][5][6][7][8][9][10][11][12][13][14] However, ICP plasma processing, used in HgCdTe, is still maturing and continued research is needed. 4,7,14 ICP plasma processing may also be used to replace conventional wet chemical clean-up, and even be used in the surface preparation for epitaxy of II-VI materials. Producing plasma processes that can be used to delineate pixels, clean surfaces, and even produce epi-ready surfaces, would allow HgCdTe to become more manufacturable.…”

Morphology of Inductively Coupled Plasma Processed HgCdTe Surfaces

“…[1][2][3][4] Several studies have also reported the effect that high-density ''dry'' electron cyclotron resonance (ECR) plasmas have on HgCdTe epitaxial properties. [5][6][7][8][9][10][11][12][13][14] However, ICP plasma processing, for use in HgCdTe, is still maturing and continued research is needed. 4,7,14,15 ICP plasma processing may also be used to replace conventional wet chemical clean-up, and can even be used in the surface preparation for epitaxy of II-VI materials.…”

“…[5][6][7][8][9][10][11][12][13][14] However, ICP plasma processing, for use in HgCdTe, is still maturing and continued research is needed. 4,7,14,15 ICP plasma processing may also be used to replace conventional wet chemical clean-up, and can even be used in the surface preparation for epitaxy of II-VI materials. Producing plasma processes that can be used to delineate pixels, etch vias, clean surfaces, and even produce epi-ready surfaces would allow HgCdTe to become much more manufacturable and even replace wet chemical etching in the factory.…”