This Small Business Innovation Research Phase I project is to eliminate the hazards of silane cylinders by investigating the feasibility of producing silane with an on-site gas generator. The generator will produce silane on-demand at low pressure ( 20-40 psig), and with low hold-up volume (2 liters). The generator will be much safer than cylinder silane (1250 psig, 3500 liters storage volume per cylinder) and eliminate the need for storage of large numbers of cylinders. Semiconductor manufacturing requires the deposition of silicon, silicon dioxide, and silicon nitride layers. These steps are applied to products as diverse VLSI circuits, memory chips, flat panel active matrix displays, photocopier drums, and large area solar cells. All of these processes require silane gas (SiH4). Silane is spontaneously flammable in air, has a toxicity exposure limit of 0.5 ppm, and explosively reacts with halogens such as chlorine. Silane is the largest volume pyrophoric gas used by the semiconductor industry. These factors make silane use dangerous in semiconductor fabrication facilities where large quantities are stored in hundreds of high pressure compressed gas cylinders. These cylinders are inherent sources of danger because of the possibility of gas release during transportation, storage, and handling. Evacuating a semiconductor facility due to a silane cylinder leak disrupts production and is very expensive. Semiconductor companies expend significant amounts on preventing and containing possible leaks from silane cylinders. These expenditures add to manufacturing costs, and decrease the competitive position of U.S. semiconductor companies. An on-site, point-of-use silane gas generator would be widely purchased by major semiconductor manufacturing companies to eliminate the environmental liability of transporting and using silane gas cylinders.
