Electrical characterization of germanium-silicon alloy

Abstract

Samples of strained germanium-silicon (Ge-Si) alloy were electrically characterized using resistivity and Hall-mobility measurements. The samples were obtained from a n-type Ge-Si strained epi-layer which was grown on a ptype substrate using MBE. The electrical characterization was performed using the van der Pauw technique. For comparison, the measurements were performed on control samples containing no germanium. Prior to initiating the measurements, the van der Pauw test structures were fabricated. The fabrication procedure involved sputter deposition of silicon dioxide, oxide patterning, deposition of aluminum metal and metal patterning. Each test structure was square-shaped and consisted of eight sets of peripheral metal contacts. The results of the electrical measurements were divided into two parts. In the first part, the resistivity of the silicon and Ge-Si samples were compared. In the second part, the Hall-mobility and carrier concentration of a representative silicon and Ge-Si sample were each studied. The effect of temperature, sourcing current and testing configuration on the measured electrical parameters were studied in each case.