Screening of Surface Passivation Processes for Germanium Channels

摘要

Candidate wet processes for native oxide removal from, and passivation of, germanium surfaces can be screened by high-productivity combinatorial variation of different process parameters on different site-isolated regions of a single substrate. Variable process parameters include the choice of hydrohalic acid used to remove the native oxide, the concentration of the acid in the solution, the exposure time, and the use of an optional sulfur passivation step. Measurements to compare the results of the process variations include attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), contact angle, atomic force microscopy (AFM), scanning electron microscopy (SEM), and X-ray fluorescence (XRF). A sample screening experiment indicated somewhat less native oxide regrowth using HCl or HBr without sulfur passivation, compared to using HF with sulfur passivation.

主权项

1. A method, comprising:
providing a substrate having a native oxide layer over a semiconductor surface; defining a plurality of site-isolated regions on the substrate; removing the native oxide layer from the semiconductor surface using different processes for at least two of the site-isolated regions; measuring an indicator of the presence native oxide in the site-isolated regions; comparing measurements of the indicator for the site-isolated regions subjected to the different processes; and screening the processes based on the comparing.