Methods and Compositions for Preparing Tensile Strained Ge on Ge1-ySNy Buffered Semiconductor Substrates

Abstract

The present disclosure describes methods for preparing semiconductor structures, comprising forming a Ge 1-y Sn y buffer layer on a semiconductor substrate and forming a tensile strained Ge layer on the Ge 1-y Sn y buffer layer using an admixture of (GeH 3 ) 2 CH 2 and Ge 2 H 6 in a ratio of between 1:10 and 1:30. The disclosure further provides semiconductor structures having highly strained Ge epilayers (e.g., between about 0.15% and 0.45%) as well as compositions comprising an admixture of (GeH 3 ) 2 CH 2 and Ge 2 H 6 in a ratio of between about 1:10 and 1:30. The methods herein provide, and the semiconductor structure provide, Ge epilayers having high strain levels which can be useful in semiconductor devices for example, in optical fiber communications devices.

1 . A semiconductor structure produced by a method comprising:
 a) forming a Ge 1-y Sn y  buffer layer on a semiconductor substrate; and   b) forming a tensile strained Ge layer on the Ge 1-y Sn y  buffer layer using an admixture of (GeH 3 ) 2 CH 2  and Ge 2 H 6  in a ration of between 1:10 and 1:30.   
     
     
         2 . A semiconductor structure comprising:
 a semiconductor substrate,   a Ge 1-y Sn y  buffer layer formed over the substrate, and   a tensile strained Ge layer formed over the Ge 1-y Sn y  buffer layer.   
     
     
         3 . The semiconductor structure of  claim 2 , wherein the tensile strained Ge layer has an essentially atomically flat surface. 
     
     
         4 . The semiconductor structure of  claim 2 , wherein the substrate comprises silicon. 
     
     
         5 . The semiconductor structure of  claim 2 , wherein y is between 0.015-0.045. 
     
     
         6 . The semiconductor structure of  claim 2 , wherein the Ge 1-y Sn y  buffer layer is at least 95% relaxed. 
     
     
         7 . The semiconductor structure of  claim 2 , wherein the symmetry of the tensile Ge layer is tetragonal. 
     
     
         8 . The semiconductor structure of  claim 2 , wherein the Ge layer has a tunable tensile strain of between 0.15% and 0.45% 
     
     
         9 . The semiconductor structure of  claim 2 , wherein the Ge layer is formed directly on the Ge 1-y Sn y  buffer layer.