沟槽形状对硅基沟槽式肖特基二极管电学特性的影响

Effect of the trench shape on the electrical properties of silicon based trench barrier schottky diode

随着对电子产品节能环保要求的提高,对广泛应用于电子产品的肖特基二极管电学性能的要求也越来越高.含金属-氧化物-半导体结构的沟槽式肖特基二极管(trench barrier Schottky diodes,TMBS)由于其优异的性能而备受青睐.沟槽结构对提高肖特基二极管性能起着至关重要的作用,但是关于沟槽形状对二极管电学性能的影响尚未见有深入的研究报道.本文提出了两种新型的沟槽结构——圆角沟槽和阶梯型沟槽.通过模拟研究发现,圆角沟槽与传统的直角沟槽TMBS器件相比,在维持同样的漏电流和正向导通电压的条件下,击穿电压可以提高15.8%.阶梯沟槽与传统直角沟槽TMBS器件相比,可以在击穿电压不减小的情况下,漏电降低35%,正向导通电压仅略有增加.这归结于圆角沟槽和阶梯沟槽对有源区内部电场强度分布的调节.

With the globally enhancing demand for the energy saving and environmental protection of electronic products, the requirement for Schottky diode which is widely used in electronic products becomes higher and higher. The trench metal-oxide-semiconductor barrier Schottky （TMBS） diode is more and more favored because of its excellent performance. The shape of the trench plays an important role in determining the electrical properties of the Schottky diode. However, there is no intensive study on this point. In this study, we propose two novel trench structures, i. e., filleted corner trench and ladder trench. By performing the simulation with Medici, it is found that compared with the traditional trench TMBS diode, the filleted corner trench TMBS diode has a breakdown voltage with 15.8% increase under the conditions of the same leakage current and the forward turn-on voltage. Also, the ladder trench TMBS diode can reduce the leakage current by 35%, while have a breakdown voltage not smaller than the right angle trench TMBS and a forward turn-on voltage only a little bit higher than the right angle trench TMBS.