【作者】 杜如峰；

【导师】 余岳辉；

【作者基本信息】 华中科技大学 ， 微电子学与固体电子学， 2004， 硕士

【摘要】 RSD(Reversely Switched Dynistor)器件是一种高速、超大功率半导体开关,具有阻断电压高、通流能力强、高dI/dt、使用寿命长和重复率较高的特点,是现代脉冲功率系统中开关器件的理想选择之一。基于特殊的等离子层触发模式,在整个器件面积上实现均匀同步开通,克服了晶闸管器件在导通过程中电流局部化的缺陷,提高了器件的通流能力,还具有纳秒级的开通速度,能满足脉冲功率系统对功率和速度的双重要求。本文通过深入研究RSD的工作原理,推导出RSD完全开通时,器件结构参数和外电路需满足的条件。只有当反向预充电荷量大于一临界值时,RSD器件才能工作在准二极管模式并实现均匀开通。进一步的研究还表明:为了有效地建立等离子库,需降低临界预充电荷量并保证P1层的注入电流大于抽取电流。减小p发射极的注入、减小p基区宽度以及提高其掺杂浓度都有助于RSD的大面积均匀同步导通,并为大量的测试结果所证实。开通电压是半导体开关器件的重要特性参数,其大小决定了器件功耗。文中理论推导得到RSD开关最大开通电压的计算公式,从中发现,减小RSD基区宽度、减小开通电流密度、尽可能降低衬底的电阻率,将显著减小最大开通电压。同时,理论分析和实验结果都表明,预充时间与磁开关延迟时间的不协调会引起开通电流的局部化,导致最大开通电压大幅增加。RSD良好的开关特性,使它在脉冲功率技术中具有广阔的应用前景,为使器件早日实现批量生产并走向市场,本文还研究了RSD的工艺并试制了多批样品。实验中,对不同阳极版图和形成阳极p+层的工艺进行了有益探索,实验结果对RSD的生产具有指导意义。更多还原

【Abstract】 RSD(Reversely Switched Dynistor) is a high speed and ultrahigh power semiconductor switch, which has characteristics of high breakout voltage、great current、high dI/dt、long lifetime and high repetitive rate etc, and it is a perfect alternative switch of pulsed power systems. RSD consists of several thousands of alternating thyristor and transistor sections and is triggered by an electron-hole layer instead of a local gate electrode. Due to the special device structure, it’s triggering process proceeds uniformly and simultaneously over the whole device area, which increases the device’s current capability.This thesis researches the principle of RSD and derives the critical condition when the device turns on. RSD would not operate in a quasi-diode mode, until it’s reversible stored charge is larger than a critical value which is decided by the internal structure and circuit parameters. In order to build an efficient plasma reservoir, the critical value should be decreased and the injection current to P1-layer should be larger than the extraction one. After a lot of experiments, several conclusions can be received: choosing a thinner and high doping concentration p-base layer、increasing the triggering voltage and decreasing the injection current from p-emitter will do good to the turn-on process of RSD.Turn-on voltage is an important characteristic of the device, which is proportional to the dissipation of RSD. In this thesis, a formula of the largest turn-on voltage is concluded. With the width and resistivity of n-base layer and turn-on current density decreased, the voltage will drop sharply. In this thesis, we have examined the reason that the device fails. The result shows that the inconsistent match between the triggering time and the saturated time of magnetic switch will induce failure, the current will be limited in a small area and the turn-on voltage will rise. <WP=6>Based on the perfect switching characteristics, RSD will be widely used in pulsed power field, should be found in markets as soon as possible. In order to solve the difficulties in fabricating, many experiments are carried out in our lab, different processes building p+ layer in anode and different masks of anode are tested, and these experimental results will help to improve the fabrication process in future. With the development of pulsed power technology and improving of the fabrication and triggering circuit of the device, RSD will be found frequently in our life.更多还原