Characterization of silicon wafer bonding by observation in transmitted infrared radiation from an extended source

The bonding quality of silicon wafers used in SOI technology, [1] was estim ated by the application of infrared transmission measurements. The investig ated wafers were directly welded at high or low temperature by using an int ermediary layer. Uniform and extended radiation source was applied. The int ensity of the radiation transmitted through the wafer was recorded by the t hermovision camera scanning the sample. The proposed way of the experiment, enabled very fast transmission visualization of the entire wafer surface a nd rough estimation of bonding quality. The more exact analysis of the geom etric parameters of the measurement set-up and transmissions of ideal and r eal semiconductor wafers shown below, enabled in some cases the determinati on of the sort and size of defect occurring between the bonding wafers. (C) 2000 Elsevier Science S.A. All rights reserved.