Passivation properties and interfacial chemistry of photochemically deposited SiO2 on Hg0.70Cd0.30Te

Abstract

SiO2 deposited photochemically at a substrate temperature of 100 °C has been evaluated as a surface passivant on Hg1−xCdxTe (x=0.30). It has been determined that the electrical properties of the (Hg, Cd)Te–SiO2 interface are dependent on the pretreatment given the semiconductor surface prior to the insulator deposition. Formation of a thin native oxide on the (Hg, Cd)Te surface during the pretreatment appears to enhance the resultant (Hg, Cd)Te–SiO2 interface properties. A significant spread in the (Hg, Cd)Te–SiO2 interface properties is observed, likely owing to the nature of how this native oxide forms and interactions between the native oxide and the SiH4 in the photochemical reactor. It is shown through neutron activation analysis that the Hg employed as a photochemical sensitizer is incorporated in the SiO2 at a concentration of 1.8 ppm.

Surface leakage current analysis of ion implanted ZnS-passivated n-on-p HgCdTe diodes in weak inversion

“…[5][6][7][8][9][10] ZnS, LPCVD-photo oxide, ECR SiNx, anodic oxide, plasma oxide, photo-chemical native oxide, anodic sulfide, anodic fluoride, in-situ CdZnTe, and interdiffused CdTe-HgCdTe heterojunction have been tried for the passivation of PV detector and photo-conductive (PC) detector. Among those ex-situ deposition methods, ZnS has been widely used for PV device fabrication because it shows relatively good passivating properties.…”

Deposition of high quality silicon dioxide on Hg1−xCdxTe by low-temperature liquid phase deposition method

“…10 In the past decades, photochemical vapor deposition ͑CVD͒ technology was conventionally used to form the passivation layer. [5][6][7][8][9] However, the deposition temperature in photo-CVD is still too high ͑Ͼ60°C͒ that it might lead to the interdiffusion of constituent atoms between the SiO 2 layer and the HgCdTe substrate. Besides, the adhesion problem due to the different thermal expansion coefficients of HgCdTe and SiO 2 , and the porous problem due to the water incorporated into the SiO 2 further degraded the SiO 2 films grown by photo-CVD technology.…”