Ion-Beam-Enhanced Surface Gettering of Semiconductor Substrates
Original Publication Date: 1985-Jul-01
Included in the Prior Art Database: 2005-Feb-18
The proposed method uses high-energy ions to damage the top surface of a semiconductor substrate which leads, during a subsequent heat treatment, to increased impurity diffusion and concentration at the substrate surface. Etching-off this surface layer leaves a cleaner substrate surface suitable for high performance semiconductor device fabrication. The gettering process is illustrated in the figures in which impurity concentrations are plotted vs the depth from the substrate surface. Solid line 1 in Fig. 1 represents the initial homogeneous impurity distribution. When the substrate surface is irradiated with a high- energy ion beam, e.g., in an ion implanter, the resulting radiation damage in the near-surface region will enhance the impurity diffusion. In a subsequent low temperature annealing process, for GaAs, e.g.