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

We report results on a study on inductively coupled plasma (ICP) etching of HgCdTe using a CH4-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 CH4 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.