Effect of Ge Composition on Infrared Detecting Performance of Strain Si/${\rm Si}_{1-{\rm x}-{\rm y}}{\rm Ge}_{\rm x} {\rm C} _{\rm y}$ Heterojunction on Preferentially Etched Silicon Substrate

Abstract

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> The p-strain Si/i-<formula formulatype="inline"><tex Notation="TeX">${\rm Si}_{1-{\rm x}-{\rm y}}{\rm Ge}_{\rm x} {\rm C} _{\rm y}$</tex></formula> heterojunctions prepared by a rapid thermal chemical vapor deposition system on an n-Si substrate with back preferentially etched were developed for fast IR detecting applications. The stress induced by the p-strain Si/i-<formula formulatype="inline"><tex Notation="TeX">${\rm Si}_{1-{\rm x}-{\rm y}}{\rm Ge}_{\rm x} {\rm C} _{\rm y}$</tex></formula> heterojunction enhanced the carrier mobility in p-Si layer, while the preferentially etching of n-Si substrate accelerated the heat dissipating and the reduction of series resistance. As a result, the device achieved a better performance than that of the conventional one without the strain Si or the preferentially etched substrate. In addition, the effects of morphology and Ge composition in the i-<formula formulatype="inline"><tex Notation="TeX">${\rm Si}_{1-{\rm x}-{\rm y}}{\rm Ge}_{\rm x} {\rm C} _{\rm y}$</tex></formula> thin film on the IR detecting performance were investigated in details. </para>