NON-DESTRUCTIVE WAFER-SCALE SUB-SURFACE ULTRASONIC MICROSCOPY EMPLOYING NEAR FIELD AFM DETECTION

摘要

A method, and corresponding apparatus (100), of imaging sub-surface features at a plurality of locations on a sample (122) includes coupling an ultrasonic wave into a sample at a first lateral position. The method then measures the amplitude and phase of ultrasonic energy near the sample with a tip (114) of an atomic force microscope (110). Next, the method couples an ultrasonic wave into a sample at a second lateral position and the measuring step is repeated for the second lateral position. Overall, the present system and methods achieve high resolution sub-surface mapping of a wide range of samples, including silicon wafers. It is notable that when imaging wafers, backside contamination is minimized.