NON-DESTRUCTIVE HIGH RESOLUTION MAPPING OF DEFECTS IN GaAs
Original Publication Date: 1989-Aug-01
Included in the Prior Art Database: 2005-Jan-28
To date, near band-edge photo-luminescence (PL) imaging of GaAs wafers affords the only non-contact and non-destructive characterization of microscopic material inhomogeneity within a depth of less than one micrometer. Material inhomogeneity refers to spatial variations in the distribution of dopants, and native defects which usually occur unintentionally, and can cause considerable variations in transistor characteristics over a wafer surface. The major source of this material inhomogeneity is associated with the accumulation or depletion of these point defects around dislocation sites during boule formation and cooling. Therefore, dislocation density and distribution have been of primary importance in measuring material inhomogeneity.