https://doi.org/10.15407/jopt.2018.53.254

Optoelectron. Semicond. Tech. 53, 254-260 (2018)

G.P Malanych, V.M. Tomashik

FORMATION OF POLISHED SURFACE OF PbTe AND Pb1-xSnxTe SEMICONDUCTOR PLATES

The PbTe and Pb1-xSnxTe solid solutions single crystals with the (H2O2–HBr–ethylene glycol)/ethylene glycol (EG) bromine-emerging mixtures has been investigated, and etching compositions have been developed and optimized along with the methods of their chemical treatment to form high-quality surface. The dependences of the chemical-mechanical polishing (CMP) rate versus dilution of the base polishing etchant by organic compound have been determined. The dissolution of these semiconductor materials in the aqueous solutions of the (H2O2–HBr–EG)/EG have been investigated, and dependences “etchant composition – etching rate” have been determined. The concentration regions of the areas of polishing and unpolishing solutions have been ascertained. It has been found that the semiconductor etching rate decreases and the polishing features of the H2O2−HBr−EG etching composition improve, when the EG content increase. The minimum value of the etching rates is achieved, when the saturation of the organic component is maximum (60 vol. %). The influence of the quantitative and qualitative etchant compositions and the chemical treatment procedures on the PbTe and Pb1-xSnxTe solid solution surface roughness have been ascertained using metallography and profilography. It has been determined that CMP of the semiconductors by (H2O2−HBr−EG)/EG solutions promote decreasing the structural damages of the substrate and obtaining the highquality polished surfaces. The polishing etchant compositions (H2O2–HBr–EG)/EG and technological procedures of the CMP for the disturbed layer elimination, controlled thinning the plates up to the reference dimension, as well as the surface layers removing and PbTe and Pb1-xSnxTe solid solution finishing polishing have been optimized.

Keywords: single crystal, lead telluride, solid solutions, etching rate, chemical-mechanical polishing.