Abstract: A method of producing an improved thin film transistor structure is provided having no source/gate or drain/gate overlap. A laser-assisted doping technique is applied to fabricate such transistors. A radiation filter is employed, which is transparent to light at the photolithography wavelength, but reflective or opaque at the laser wavelength. Eliminating source/gate and drain/gate overlap significantly reduces or eliminates parasitic capacitance and feed-through voltage between source and gate. Short-channel a-Si:H thin film transistors may be obtained having high field effect mobilities. Improved pixel performance and pixel-to-pixel uniformity is provided.

Abstract: A method of producing an improved thin film transistor structure is provided having no source/gate or drain/gate overlap. A laser-assisted doping technique is applied to fabricate such transistors. A radiation filter is employed, which is transparent to light at the photolithography wavelength, but reflective or opaque at the laser wavelength. Eliminating source/gate and drain/gate overlap significantly reduces or eliminates parasitic capacitance and feed-through voltage between source and gate. Short-channel a-Si:H thin film transistors may be obtained having high field effect mobilities. Improved pixel performance and pixel-to-pixel uniformity is provided.

Abstract: This invention relates to a method of altering the electrical characteristics of a material through a laser ablation process. It can achieve high doping levels and shallow junctions at low temperatures, which are desirable in the fabrication of thin film transistors.

Abstract: An amorphous silicon thin film transistor (a-Si TFT) or other a-Si device is produced by depositing and lithographically patterning a layer of doped semiconductor material such as microcrystalline or polycrystalline silicon to produce a conductive lead. The semiconductor material is deposited over an insulating region and over an exposed part of an amorphous silicon layer. The insulating region has an edge that is over and approximately aligned with an edge of a gate region. The doped semiconductor layer therefore forms a junction to the amorphous silicon layer at the edge of the insulating region, approximately aligned with the edge of the gate region. Self-aligned lithographic patterning is performed in such a way that the conductive lead overlaps the insulating region by a distance that is no more than a maximum overlap distance. The maximum overlap distance can, for example, be no more than 1.0 .mu.m, and can be 0.5 .mu.m.

Abstract: An array includes cells, each with a bottom gate amorphous silicon thin film transistor (a-Si TFT). Each a-Si TFT has an undoped amorphous silicon layer over its gate region and extending beyond its edges. Each a-Si TFT also has an insulating region with edges approximately aligned with the edges of its gate region. Two channel leads of doped semiconductor material such as microcrystalline silicon or polycrystalline silicon are on the undoped amorphous silicon layer, each overlapping an edge of the insulating region by a distance that is no more than a maximum overlap distance, which in turn is no more than 1.0 .mu.m.

Abstract: A low temperature process for dehydrogenating amorphous silicon using lasers. Dehydrogenation occurs by irradiating one or more areas of a hydrogenated amorphous silicon layer with laser beam pulses at a relatively low energy density. After the multiple laser pulse irradiation at a relatively low energy density, the laser energy density is increased and multiple irradiation at a higher energy density is performed. If after the multiple irradiation at the higher energy density the amorphous silicon hydrogen content is still too high, dehydrogenation proceeds by multiple irradiations at a yet higher energy density. The irradiation at the various energy densities can result in the formation of polysilicon due to melting of the amorphous silicon layer. As irradiation may be selectively applied to the amorphous silicon, an integral amorphous silicon-polysilicon structure may be formed.

Abstract: A process is provided for fabricating multi-discrete-phase binary Fresnel acoustic and optical lenses through the use of standard microelectronic fabrication techniques, thereby enabling such lenses to be produced repeatedly and economically to exacting design specifications.