Abstract: A method for fabricating graded heterojunction electronic devices uses laser melting and recrystallization of layered films to create an epitaxial alloy heterojunction. Layering an appropriately doped polysilicon film over a germanium film that has been deposited upon a base region allows the laser melting and recrystallization thereof to create a graded epitaxial silicon/germanium alloy heterojunction. Other film materials could be selected for other graded heterojunctions. The method provides for sufficient device design flexibility including deeper junction formation and reduces the problems associated with contamination.

Abstract: A non-contact method to impart a texture to a surface using laser irradiation uses an excimer laser to illuminate a sample immersed in a halocarbon ambient thereby initiating a photo/thermal chemical reaction which etches the sample only in the area illuminated with sufficient laser fluence. The resulting etched area can be repetively illuminated and etched to provide a textured surface to reduce extraneous reflections, or for micromachining, decorative texturing and marking. This technique is particularly well suited to improve the performance of backside illuminated CCDs by reducing the background (dark) signal, increase resolution and responsivity uniformity. The technique is compatible with other laser processing procedures and can be implemented with a variety of CCD enhancements such as improved dark current and blue response from laser doping or activation of backside implants.