MOS transistor technology - employs high dose ion implantation and simultaneous gate and field oxide growth

摘要

This technology employs a method of producing MOS transistors whereby the field oxide and gate oxide are produced simultaneously, thus avoiding the problems of nitride separation, tension stresses and the white ribbon effect. This is accomplished by implanting high dose ions in the field oxide regions and then building up the gate-and field oxide in a temperature of between 550 deg.C and 700 deg.C simultaneously. The silicon substrate is masked with a photo-lacquer coating (2). The implanting of the high dose ions in the field oxide region results in the formation of regions (3) in the substrate. During the subsequent oxidation at a temperature of 620 deg.C an oxide growth ratio of 6 to 1 is achieved. Repetition of the process increases oxide growth even further.