發(fā)布時間：2018-04-27 20:48

  本文選題：碳化硅 + 肖特基二極管　； 參考：《南京理工大學》2017年碩士論文

【摘要】：作為第三代半導體材料的代表,SiC單晶具有禁帶寬度大、飽和電子漂移速率大、臨界擊穿場強高和熱導率高等優(yōu)勢,可以用于制備耐高溫、散熱好、耐高壓、高頻大功率器件。目前,SiC單晶已經(jīng)被廣泛應用于肖特基二極管(SBD)、pin二極管以及結勢壘肖特基二極管(JBS)等功率器件的制備。在這些功率器件中,SiC JBS二極管具有SBD二極管和pin管兩者的優(yōu)勢,一直是研究的熱點之一。目前SiC JBS二極管研究主要集中在離子注入和結終端技術方面。本文基于模擬的方法,研究了 n型4H-SiC材料中A1注入結深、濃度分布與注入角度、緩沖層、能量和劑量的關系,優(yōu)化了注入深度500nm,濃度均勻分布的注入條件,并進行了常溫注入實驗。注入完成后,進一步探討了保護方式、溫度等對SiC晶圓激活效果,注入條件和退火保護方式對SiC表面粗糙度的影響。在激活完成后,在材料上生長了一層Ni并進行退火,分析了激活濃度對Ni與A1注入形成的p-SiC的歐姆接觸的影響。實驗結果表明以4°偏角注入,用100nmSiO_2作為緩沖層進行注入,以1750℃用SiC上下夾片保護進行退火,可以得到表面粗糙度為0.862nm,激活濃度為4.25×1019 cm-3的p-SiC。1050℃-2min的歐姆接觸退火條件為最優(yōu)條件,制備出比接觸電阻率為4.10mΩ.cm2的歐姆接觸。輕微的過刻蝕有利于提高肖特基接觸性能。同時通過對場板長度的優(yōu)化,對場限環(huán)參數(shù)的模擬結合離子注入制備出了開啟電壓在1V、擊穿電壓1300V、理想因子1.49、勢壘高度1.07eV的SiCJBS器件。
[Abstract]:As the representative of the third generation semiconductor material, sic single crystal has the advantages of wide band gap, high saturated electron drift rate, high critical breakdown field strength and high thermal conductivity. It can be used to fabricate high-temperature, heat-dissipation, high-voltage and high-frequency high-power devices. At present, sic single crystal has been widely used in the fabrication of Schottky diode (SBD) pin diode and junction barrier Schottky diode (JBS). Among these power devices, sic JBS diodes have the advantages of both SBD diodes and pin diodes. At present, the research of SiC JBS diode is mainly focused on ion implantation and junction terminal technology. Based on the simulation method, the relationship between Al implantation depth, concentration distribution and implantation angle, buffer layer, energy and dose in n-type 4H-SiC is studied. The implantation conditions of 500 nm implantation depth and uniform concentration distribution are optimized. The experiment of injection at room temperature was carried out. After the injection, the effects of protection, temperature and so on on the activation of SiC wafer, the effect of injection conditions and annealing protection on the surface roughness of SiC were discussed. After activation, a layer of Ni was grown on the material and annealed. The effect of activation concentration on ohmic contact of p-SiC implanted with A1 was analyzed. The experimental results show that 4 擄angle is injected, 100nmSiO_2 is used as buffer layer, and SiC upper and lower clamps are used for annealing at 1750 鈩，

本文編號：1812294