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在功率半导体器件中,高的反向击穿电压和低的正向导通电阻之间的矛盾关系是影响其发展的主要因素之一,选用超结结构替代功率半导体器件中的传统电压支持层能够有效缓解这一矛盾关系。该文设计和实现了一种超结肖特基二极管,其中的电压支持层采用P柱和N柱交替构成的超结结构。在器件的制作方面,选用成熟的单步微电子工艺,通过4次N型外延和4次选择性P型掺杂来实现超结结构。为便于对比分析,设计传统肖特基二极管和超结肖特基二极管的电压支持层厚度一致,且超结结构中P柱和N柱的杂质浓度均和传统肖特基二极管的电压支持层浓度一致。测试得到传统肖特基二极管的反向击穿电压为110 V,而超结肖特基二极管的反向击穿电压为229 V。表明采用超结结构作为功率半导体器件的电压支持层能够有效提高反向击穿电压,同时降低器件的正向导通电阻,并且当P柱区和N柱区内的电荷量一致时器件的击穿电压最高。
In power semiconductor devices, the contradiction between the high reverse breakdown voltage and the low forward resistance is one of the main factors affecting its development. The use of a super-junction structure to replace the conventional voltage support layer in power semiconductor devices can Effectively alleviate this contradiction. In this paper, a super-junction Schottky diode is designed and implemented. The voltage support layer adopts the super-junction structure composed of P-pillar and N-pillar alternately. In the fabrication of the device, the mature single-step microelectronic process is adopted, and the super-junction structure is realized by 4 times of N-type epitaxy and 4 times of selective P-type doping. In order to facilitate comparative analysis, the design of the traditional Schottky diode and super-junction Schottky diode voltage support layer thickness, and the super-junction structure P-pillar and N-pillar impurity concentration and traditional Schottky diode voltage support layer concentration Consistent. The reverse breakdown voltage of the conventional Schottky diode was 110 V, while the reverse breakdown voltage of the super-junction Schottky diode was 229 V. It is shown that using the super junction structure as the voltage supporting layer of the power semiconductor device can effectively increase the reverse breakdown voltage and reduce the forward conduction resistance of the device, and the breakdown of the device when the charges in the P column region and the N column region coincide The highest voltage.