英文翻译及文献电子电子功率半导体

1、New Generation of High -Power Semiconductor Closing Switches for Pulsed Power ApplicationsI. IntroductionSolid state semiconductor switches are very inviting to use at pulsed power systems because these switches have high reliability, long lifetime, low costs during using, and environmental safety d

2、ue to mercury and lead are absent. Semiconductor switches are able to work in any position, so, it is possible to design systems as for stationary laboratory using, and for mobile using. Therefore these switches are frequently regarded as replacement of gas-discharge devices-ignitrons, thyratrons, s

3、park gaps and vacuum switches that generally use now in high-power electrophysical systems including power lasers.Traditional thyristors (SCR) are semiconductor switches mostly using for pulse devices. SCR has small value of forward voltage drop at switch-on state, it has high overload capacity for

4、current, and at last it has relatively low cost value due to the simple bipolar technology. Disadvantage of SCR is observed at switching of current pulses with very high peak value and short duration. Reason of this disadvantage is sufficiently slow process of switch-on state expansion from triggeri

5、ng electrode to external border of p-n junction after triggering pulse applying. This SCR feature is defined SCR using into millisecond range of current switching. Improvement of SCR pulse characteristics can be reached by using of the distributed gate design. This is allowed to decreasethe time of

6、total switch-on and greatly improve SCR switching capacity. Thus, ABB company is expanded the semiconductor switch using up to microsecond range by design of special pulse asymmetric thyristors (ASCR). These devices have distributing gate structure like a GTO. This thyristor design and forced trigge

7、ring mode are obtained the high switching capacity of thyristor (I p =150kA, Tp =50 卩 s, di/dt = 18kA/卩 s,single pulse). However, in this design gate structure is covered large active area of thyristor (more than 50%) that decreasethe efficiency of Si using and increasecost of device.Si-thyristors a

8、nd IGBT have demonstrated high switching characteristics at repetitive mode. However, such devices do not intend for switching of high pulse currents (tens of kiloamperes and more) because of well-known physical limits are existed such as low doping of emitters, short lifetime of minority carriers,

9、small sizes of chips etc.Our in vestigati on have obta ined that switches based on reverse -switched dini stors are more perspective solid-state switches to switch super high powers at microsecond and submillisecond ranges. Reverse - switched dinistors (RSD) is two-electrode analogue of reverse cond

10、ucting thyristor with monolithical integrated freewheeling diode in Si. This diode is connected in parallel and in the back direction to the thyristor part of RSD. Triggering of RSD is provided by short pulse of trigger current at brief applying of reversal voltage to RSD. Design of RSD is made thus

11、 that triggering current passes through diode areas of RSD quasiaxially and uniformly along the Si structure area. This current produces the oncoming injection of charge carriers from both emitter junctions to base regions and initiates the regenerative process of switch-on for RSD thyristor areas.

12、Such method of triggering for this special design of Si plate is provided total and uniform switching of RSD along all active area in the very short time like as diode switch-on. The freewheeling diode integrated into the RSD structure could be used as damping diode at fault mode in the discharge ci

13、rcuit. This fault mode such as breakdown of cable lines can lead to oscillating current through switch.It has been experimentally obtained in that semiconductor switches based on RSD can work successfully in the pulsed power systems to drive flash lamps pumping high-power neodymium lasers. It was sh

14、own in that RSD-switches based on RSD wafer diameter of 63 mm (switch type KRD-25-100) and RSD-switches based on RSD wafer diameter of 76 mm (switch type KRD-25-180) can switch the current pulses with submillisecond duration and peak value of 120 kA and 180 kA respectively. Three switches (switch ty

15、pe KRD -25-180) connected in parallel were successfully tested under the following mode: operating voltage Vo= 25 kV, operating current Ip = 470 kA, and transferred charge Q = 145 Coulombs.During 2000 -2001, the capacitor bank for neodymium laser of facility LUCH was built at RFNC-VNIIEF. This bank

16、including 18 switches type KRD-25-100 operates successfully during 5 years without any failures of switches.This report is submitted results of development of new generation of solid state switches having low losses of power and high-current switching capacity.II. Development of RSD s next generatio

17、nThe technology of fabrication of new RSD structure has been developed to increase the switching capacity. This new structure is SPT (Soft Punch Through)-structure - with “soft closing of space-charge region into buffer n-layer.Decreasing of n-base thickness and also improving of RSD switch-on unifo

18、rmity by good spreading of charge carriers on the n-layer at voltage inversion are provided decreasing of all components of losses energy such as losses at triggering, losses at transient process of switch-on, and losses at state-on. Our preliminary estimation was shown that such structure must prov

19、ide the increasing of operating peak current through RSD approximately in 1.5 times.Investigations were carried out for RSD with blocking voltage of 2.4 kV and Si waferdiameters of 63, 76, and 100 mm by special test station. The main goal of these investigations is definition of maximum permissible

20、level of peak current passing through single RSD with given area. Current passing through RSD and voltage drop on RSD structure during current passing are measured at testing. In Fig.1 waveforms of peak currents and voltage drops is shown for RSD with size of 76 mm and blocking voltage of 2.4 kV.b)F

21、ig.1. Waveforms of pulse curre nt (a) and voltage drop (b) for RSD with wafer size of 76 mm andblocki ng voltage of 2.4 kVIn accord ing with study program curre nt was slowly in creased un til maximum permissible level Ipm. When this level was reached the sharp rise of voltage and than the same shar

22、p decay of voltage for curve U(t) was observed. Reas on of voltage rise is stro ng decreasing of carrier mobility at high temperature, and reason of voltage decay is quick modulati on of cha nnel con ductivity by thermal gen erated plasma that is appeared in accordancewith sharp exponential dependen

23、cefor own concentration of initial silicon into base areas of RSD at temperature of 40- 6000C.Tests were show n that this sharp rise of voltage at maximum permissible curre nt does not lead to immediate fault of RSD. RSD keeps its blocking characteristic. However, after passing of such current I pm

24、we can observe the appearanceof erosion from cathode for aluminum metallizati on of RSD con tacts, and this fact is evide nee of borderli ne state of device. The subsequent increasing of current (more than I pm) leads to fusing of Si structure. Therefore, level Ipm is the reference position to defin

25、e the value of operation peak current for RSD-switch un der long and repeated many times operat ing mode.We have determined that operating peak current I pw must be less than 80% from levelI pm. This ratio was confirmed by calculations and results of tests under Ipw mode (several thousands of shots)

26、.Data of test results for new generation of RSD with the various diameter of Si wafer are shown in Table 1. In this Table for comparing results of the same tests for the first generation of RSD with size of 63 and 76 mm are shown.III. Switches based on RSD of new generationNew reverse switched dinis

27、tors is manufactured in two variants. RSD of the first variant is in the low-profile metal-ceramic housing. The second variant is RSD fabricated without housing and with additional protection of periphery area from external action.Dinistors placed into housing can be used for work under as mono - pu

28、lse mode and repeated - pulse mode. If repeated-pulsedmode using the forced cooling of semiconductor devices and using of heatsinks to both side of pellet must be made. Dinistors without housing connects in series, and such assembly could be placed into a single compact housing. However, such assemb

29、ly can work under mono-pulse mode only.Operating voltage for switch typically exceeds blocking voltage of single RSD (UBO w 2400V),thus switch is in eluded several RSDs conn ected in series. Fig.2. Reverse switched dinistors for peak current from 200 kA to 500 kA and blocking voltage of 2400 V , enc

30、apsullated in hermetic metal -ceramic housing and without housing (RSD sizes of 64, 76, and 100 mm).Number of RSDs included in assembly depends on operating voltage of switch. Therefore, technical problem of switch development is mainly optimization of design for assembly of several dinistors connec

31、ted in series. A lot of special investigations have carried out such as choice of optimum materials to provide best contacts between RSDs, calculation of dynamic forces to clamp assembly, etc. These investigations are provided small and stable transition electrical and thermal resistances between RS

32、Ds that guarantees long and reliable performance of switch. Especial computer technique has developed to select RSDs for connection in series. At this RSD selection value of leakage current and stability of blocking volt-amps diagram are measured especially. This selection technique is allowed exclu

33、de the voltage dividers using for equalization of static voltage for each RSD at assembly. Thus, after such selection switch design can simplify, sizes of switch are increased approximately in 1.5 times, and cost of switch is increased too.This solid state switch has operating voltage of up to 25 kV

34、dc, operating peak current of up to 300 kA at current pulse duration of up to 500 卩 sRFNC-VNIIEF plans to use such switch at capacitor bank of laser facility-6”. This“sIwsiktrcah is included 15 RSDs with sizeof 76 mm and blocking voltage of 2.4 kV connected in series and encapsullated into dielectri

35、c housing. Very high level of switched power density per volume unit has reached by this switch design. This value is of 2.5 106W/cm3, and this value is exceeded in the several times the same switches based on pulse thyristors.Triggering of all RSDs in switch is provided by the single trigger genera

36、tor which connected to switch in parallel. Triggering current passessimultaneously through all RSDs connected in series. Such triggering type is allowed to increase efficiency and reliability of triggeri ng circuit for this switch, and this is one more adva ntage of RSD -switch compared to switch ba

37、sed on thyristors.For new generation of RSD trigger current has peak value between 1-1.5 kA at pulse duration between 1.52 卩 s. These values are less if32times compared to values of trigger current for RSD of the first generation.IV. ConclusionNext generation of reverse-switched dinistors and RSD -s

38、witches has been developed Tests of these switches are shown that all - time high level of switched power density per volume unit has reached. The switches are able to work under as mono-pulse and pulse-repeated modes and suitable for many applications of pulsed power.应用于脉冲电源设备的新一代高功率半导体关闭开关1 导言 固态半

39、导体开关普遍使用在脉冲功率系统，因为这些开关具有可靠性高，寿命长， 使用成本低，并且由于汞和铅的量少能够保证环境的安全。半导体开关可以在任何位置 工作，所以，它可以在固定的实验室使用，并可以为移动设备设计系统。因此这些开关 被频繁的看作是可以替代气体放电装置、放电管、闸流管，火花隙缝隙和现在普遍使用 的高能量电板系统包括功率激光器的真空开关。传统的晶闸管是大多应用在脉冲设备的半导体开关。 它在早前的正向电压下拉开关 的状态有小的价值，它对电流具有超负荷的能力，最后它由于简单的两极技术它拥有相 对较低的成本价值。它的缺点是高峰值的电流脉冲和较短的持续时间。导致这种缺点的 原因是在触发脉冲设置后从

40、触发电极到到外部连接进程十分缓慢。 它的这种特征使得它 应用在现时配电的毫秒范围内。 改进晶闸管脉冲的特点可以通过改进分布式门设计达到 效果。这就允许减少总的接通时间和极大提高配电的能力。因此，ABB公司扩大半导体开关的使用一直到对特别脉冲的不均匀晶闸管的微秒范围的设计。 这些装置分布闸门的 结构类似于GTQ这个晶闸管的设计和强迫的触发模式获得晶闸管的高配电能力。然而，这个门的结构覆盖了晶闸管的大活动面积， 从而降低了硅利用的效率并增加了装置的成 本。硅晶闸管和 IGBT 已经证明在重复模式下的高配电特性。然而，这样的设备因为众 所周知的屋里限制不打算供给高脉冲电流的配电普遍存在，如存在使用兴

41、奋剂的排放 低，少数载流子的载波寿命短，小尺寸的芯片等。我们的调查已取得的基于逆向的接通在毫秒和微妙范围内接通显现为从使用电晶 体管转换为接通高能量开关。 逆向在硅里的综合的单片电路惯性滑行的二极管逆向的晶 闸管是两极类似物。这个二极管平行的连接，在后方与RSD勺晶闸管部分连接。触发RSD 为提供短期触发脉冲电流简短逆转的应用电压区。RSD的设计触发电流通过二极管领域的相对标准偏差和均匀沿着硅的结构范围。 目前生产的这即将来临的电荷携带者的生产 过程从发射连接到基本区域和启动再生过程开关上的RSD为晶闸管地区。这种提供RSD开关的总和或统一的设置对于硅的特别设计的触发方法在非常少的时间应用在所

42、有的 活动面积类似二极管的接通。该惯性滑行的二极管集成到RSD结构可以作为阻尼二极管 在故障模式的放电电路。这种故障模式如故障的电缆线可能会导致振荡电流开关通过。它已获得的RSE为基础的实验半导体开关可以成功地在脉冲功率系统内推动闪存灯 泵浦高功率的钕激光。结果表明在该区域市交换机基于RSD为晶圆直径六三毫米和RSD开关的关于区晶圆直径为 76 毫米可以切换当前的脉冲持续时间和峰值。三个开关并联 成功试射以下模式：经营电压 Vo = 25 kV，经营电流=470 kA，并转移电荷=145库。在2000 - 2001年，电容器钕激光射线的设施建在 RFNC- VNIIEF。这种电容器组， 包括类

43、型KRD - 25 - 100的18个开关，成功地没有任何失败的经营了 5年开关。本报告提交结果发展新一代的固态开关， 具有低功耗和损失高的交换容量。2 RSD 下一代的发展新的RSD结构的制造技术已经发展用于增加开关的容量。这种新的结构标准贯入试验结构与“软”闭幕空间电荷区域变成缓冲层通过电压转变在缓冲层上的交换载体的良好传递，氮基厚度的减少和提高RSD开关的均匀被提供降低所有损失能量的组成成分，像扳机的缺损、开关过程短暂的缺损以及 基层的缺损。我们的初步估计结果表明，这种结构必须通过RSD使运转电流的峰值不断增加，大约在 1.5 倍以上。调查进行了阻断电压为 2.4 kV 及硅晶片直径为 63、76 和 100毫米的特殊测试站。 这些测试的主要目标是测定在已给范围内通过单个RSD勺最大允许水平的高峰电流。在电流通过的瞬间，通过RSD的电流和在RSD结构上的电压都在测试中被测量。在图一中， 电流峰值的波形和电压的通过用尺寸为 76毫米，阻断电压为2.4千伏的RSD显示。直到最大许可等级为 I 极，电流研究项目的一致慢慢的增加。当这个极达到，对电 压的尖锐程度和同一衰减电压曲线 U进行了观察。电压上升的原因是在高温度情况下的 自动载体的强大增加