Laser recrystallized silicon/PLZT smart spatial light modulators for optoelectronic computing

By integrating materials for electronic processing with light modulating materials, the computational power of electronics can be combined with the communication power of optics. These light modulating devices integrated with silicon (Smart Spatial Light Modulators or S-SLMs) form a key component of highly parallel fine grain optoelectronic computers. Spatial light modulators developed using the combination of silicon with PLZT (a ferroelectric light modulating ceramic) meet the system requirements for optoelectronic computing. PLZT can be integrated with silicon by depositing a thin layer of polysilicon on the top. However, the quality of polysilicon does not allow the fabrication of circuits of high complexity. It is possible to enlarge polysilicon grain size by melting and solidifying it in a controlled manner. A dual beam laser recrystallization technique has been developed for this purpose. This thesis involves the development and the application of this technique to fabrication of S-SLMs. The goal is to increase the number of transistors in an S-SLM while keeping the array yield of such devices above acceptable levels for optoelectronic computer systems. For this purpose, a NMOS process in laser recrystallized silicon on PLZT has been developed. Arrays with up to 12 transistor unit cell complexity have been fabricated using this technology.