半绝缘GaAs光导开关中EL2深能级研究
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摘要
半导体光导开关(Photoconductive Semiconductor Switches简称PCSS's)是利用超快脉冲激光器与光电导体(如GaAs,InP等)相结合形成的一类新型器件。光导开关具有优良的电器特性,如上升时间短(几十皮秒量级)、响应速度快、光电隔离好、抗干扰能力强、动态范围宽等特点。在超高速电子学、超宽带雷达、超宽带通讯和瞬态电磁波技术等领域有着广泛的应用前景。本文主要研究了半绝缘GaAs光导开关中EL2本征深施主能级,由于光导开关中EL2能级的存在,使得开关可以吸收比本征吸收限大的激光脉冲;本文分别讨论了光子能量为1.13eV和1.167eV的光照射光导开关时候的吸收机制。对于用1.13eV的光淬灭EL2能级时,表现为光电导先增加到最大值后减小到一极小值后又缓慢增大,最终达到一个饱和值的现象;此现象和半绝缘GaAs中EL2能级中的EL2~0中性能级向亚稳态能级EL2~*的转化、及EL2~+能级有关。而光子能量为1.167eV即1064nm激光脉冲触发光电导开关时有光电导的产生,在1064nm激光脉冲触发下,光导开关可以工作在线性工作模式、非线性工作模式和复合工作模式;在三种工作模式中EL2能级发挥不同的作用,尤其在复合工作模式中的延迟效应,可以利用EL2能级很好的解释这个延迟效应。在GaAs光导开关超短电脉冲响应特性中研究了输出超短电脉冲的上升时间和触发光能之间的关系及其原理分析。本文在讨论上面内容前,先对半绝缘GaAs材料中的本征缺陷EL2能级的结构模型,EL2的亚稳态能级特性,EL2在半绝缘GaAs晶体中的分布和其浓度测量,还有热处理对EL2能级的影响等进行讨论。由于光淬灭实验中所用的材料电参数的热稳定性影响,所以本文中也对半绝缘GaAs的半绝缘特性补偿机制和电参数的热稳定性进行了详细讨论。
Photoconductive Semiconductor Switches(PCSS's)is a new semiconductor device that combines ultra-short laser pulse with photoelectric semiconductor(GaAs,InP and so on). PCSS's have the excellent base operating characteristic of electrical apparatus,such as the short rise-time of electromagnetic pulse,fast response speed,wide change of dynamic state,the good ability of optoelectronic isolation and anti-interference.Therefore it is widely used in some field,such as ultra-speed electronics,ultra-band radar,ultra-band communication and the technology of transient electromagnetic wave.The intrinsic donor level deep EL_2 in semiconductor GaAs is investigated in this paper.Based on the EL_2 donor level,the laser pulse which is longer than intrinsic absorption edge can be absorbed.The absorption principle when PCSS's are exposed by laser in 1.13eV and 1.167eV photon energy.In the condition of 1.13eV photon energy,photo-conductance deduces to a minimum before rises to a maximum,finally, arrives at a saturation value.The phenomenon is connected with the conversion from EL2~0 neutral energy level to metastable energy level EL2~* and EL2~+ level in semiconductor GaAs. When the PCSS is irrigated by 1064nm laser,there are three modes,linear mode,nonlinear mode and compound mode.The EL2 energy level plays different roles in three modes. Especially in the compound mode,the EL2 energy level can be well used to explain the late effect.The relationship between rise time of output ultra-short pulse and laser is analyzed in this paper.The structural model of EL2 trap,the characteristic of metastable energy level EL2 the distribution of EL2 in semiconductor GaAs,the measure of density and the affection of heating processing are discussed at the beginning of this paper.Based on the affection of heat endurance of material electrical parameter in the experiment,the heat endurance of electrical parameter and semiconductor character's compensation principle of semiconductor GaAs are detailed discussed in this paper.
Photoconductive Semiconductor Switches(PCSS's)is a new semiconductor device that combines ultra-short laser pulse with photoelectric semiconductor(GaAs,InP and so on). PCSS's have the excellent base operating characteristic of electrical apparatus,such as the short rise-time of electromagnetic pulse,fast response speed,wide change of dynamic state,the good ability of optoelectronic isolation and anti-interference.Therefore it is widely used in some field,such as ultra-speed electronics,ultra-band radar,ultra-band communication and the technology of transient electromagnetic wave.The intrinsic donor level deep EL_2 in semiconductor GaAs is investigated in this paper.Based on the EL_2 donor level,the laser pulse which is longer than intrinsic absorption edge can be absorbed.The absorption principle when PCSS's are exposed by laser in 1.13eV and 1.167eV photon energy.In the condition of 1.13eV photon energy,photo-conductance deduces to a minimum before rises to a maximum,finally, arrives at a saturation value.The phenomenon is connected with the conversion from EL2~0 neutral energy level to metastable energy level EL2~* and EL2~+ level in semiconductor GaAs. When the PCSS is irrigated by 1064nm laser,there are three modes,linear mode,nonlinear mode and compound mode.The EL2 energy level plays different roles in three modes. Especially in the compound mode,the EL2 energy level can be well used to explain the late effect.The relationship between rise time of output ultra-short pulse and laser is analyzed in this paper.The structural model of EL2 trap,the characteristic of metastable energy level EL2 the distribution of EL2 in semiconductor GaAs,the measure of density and the affection of heating processing are discussed at the beginning of this paper.Based on the affection of heat endurance of material electrical parameter in the experiment,the heat endurance of electrical parameter and semiconductor character's compensation principle of semiconductor GaAs are detailed discussed in this paper.
引文
[1]G.M.Loubriel,M.W.O'Malley,and F.J.Zutavern.Toward Pulased power uses for Photoconductive Semiconductor Switches[C].Proc.6~(th)IEEE Pulsed Power Corfference.Arlington.US.1987:577-603.
[2]G.M.Loubriel,F.J.Zutavern.and A.G.Baca et al.Photoconductive semiconductor switches[J].IEEE Trans.Plasma.Sci.,1997,25(2):124-130.
[3]G.M.Loubriel,F.J.Zutavern.Photoconductive semiconductor switch experiment for pulse application [J].IEEE Tran.on electron device.1990,37(12):2472-2477.
[4]Prather,W.D.Baum,C.E.Lehr,J.M.O'Loughlin,et al.Ultra-wideband source and antenna research [J].IEEE Trans.Plasma Science,2000,28.(5):1624-1630.
[5]Schoenberg,J.S.H.Burger,et al.Ultra-wideband source using gallium arsenide photoconductive semiconductor switches[J].IEEE Trans.Plasma Science,1997,25(2):327-334.
[6]Weiss M.D.,Crites M.H.,et al.Time-domain optical sampling of switched-mode microwave amplifiers and multipliers[J].IEEE Trans.Microwave Theory and Techniques,1999,47(12):2599-2604.
[7]S.Jayaraman,C.H.Lee.Observation of two-photo conductivity in GaAs with nanosecond and picosecond light pulse[J].Appl.Phys.Lett,1972,20(5):392-395.
[8]D.H.Auston.Picosecone opoelectronic swithing and gating in sillicon[J].Appl.Phys.Lett,1975,26(2):101-103.
[9]C.H.Lee et al.Picosecond optoelectronic switching in GaAs[J].Appl.Phys.Lett,1977,30(3):84-86.
[10]W.C.Nunnally,R.B.Hammond.80MW photoconductor power switches[J].Appl.Phys.Lett,1984,44(3):980-982.
[11]G.M.Loubriel,et al.Towards Pulsed Power Uses for Photoconductive Semiconductor Switches:Closing Switches[J].6~(th)IEEE Pulsed Power Conf.1987,145-148.
[12]S.D.Thibaut.Optically Activated Switching Ⅱ[J].PROC.SPIE,1992,1632(4):167-176.
[13]R.A.Fork,et al.Optical probe technique for avalanching photoconductors[C].Proc.8~(th)IEEE Pulsed Power Conference,1991:29-32.
[14]F.J.Zutavern,et al.Measurement of filament velocity and reduced triggering energy[J].Opticalluy Activated Switching Ⅳ,Proc.SPIE.1994,2343(8):21-31.
[15]J.M.Yee,et al.Modeling the effect of deep impurity ionization on GaAs photoconductive switches [J].Proc.SPIE Optically Activated Switching Ⅱ,1962,1632(5):21-28.
[16]W.T.White,et al.Modeling GaAs high-voltage subnanosecond photoconductive switches in one spatial dimension[J].IEEE Trans.Electron Devices,1990,37(12):2532-2541.
[17]R.P.Brinkmann,et al.Analysis of time-dependent current transport in an optically controlled Cu-compensated GaAs switch[J].Proc.SPIE Optically Activated Switching Ⅱ,1992,1633(7):262-273.
[18]H.Zhao,et al.Avalanche injection model for the lock-on effect in Ⅲ-Ⅴ power photoconductive Switches[J].J.Appl.Phys.1993,73(4):1807-1812.
[19]Shi Wei.Optically activated charge domain model for high-gain GaAs Photoconductive Switches [J].Chinese Journal of Semiconductors,2001,22(12):1481-1485.
[20]黄裕年.用光导半导体开关产生高功率微波[J].半导体光电,1998,19(2):101-106.
[21]D.H.Auston.Picosecond optoelectronic switching and gating in silicon [J].Appl.Phys.Lett,1975,26(6):101-103.
[22]C.H.Lee.Picosecond photoconductivity and its applications[J].IEEE Trans.J.Quantum Electronics,1981,17(2):2098-2107.
[23]C.H.Lee.Picosecond Optoelectronic Devices[C].Academic Press,New York,1984:126-129.
[24]G.M.Loubriel,et al.Towards pulsed power uses for Photoconductive Semiconductor Switches:Closing Switches[C].6~(th)IEEE Pulsed Power Conf.,1987:145-148.
[25]龚仁喜,张义门,石顺祥,张同意.高压GaAs光导开关的锁定及延迟效应机理分析[J].光学学报,2001,12(11):1372-1376.
[26]G M Martin,et al.Compensation mechanisms in GaAs[J].J Appl Phys,1980,51(5):2480-2852.
[27]R.A.Morrow.Model of EL2 formation in GaAs[J].Appl Phys,1991,70(11):6782-6787.
[28]W C Michel.Temperature dependence of the persistent photocurrent in czochralski gallium arsenide [J].Phys Rev,1990,B41(17):12086-12091.
[29]杨瑞霞.半绝缘LECGaAs中主要缺陷特性及其对材料和器件性能影响的研究[D].西安:西安交通大学,1998.
[30]王季陶,刘明登著.半导体材料[M].北京:高等教育出版社,1990:427-498.
[31]J Lagowski et al..Origin of 0.82eV electron trap in GaAs and tis annihilation by shallow donors[J].Appl Phys Lett,1982,40(4):342-344.
[32]赵会娟,牛憨笨.光导开关锁定机理的理论分析[J].光子学报,1997,26(1):61-65.
[33]杨瑞霞等.非掺杂半绝缘LEC GaAs的光电流谱[J].光谱学与光谱分析,1999,19(1):22-24.
[34]刘力锋.热处理对非掺杂半绝缘LEC GaAs本征缺陷及电特性影响的研究[D].河北:河北工业大学,2002.
[35]徐波等.EL2光淬灭过程中光电导增强现象原因新探[J].半导体学报,1994,15(5):322-328.
[36]谢孟贤,刘诺.化合物半导体材料与期间[D].成都:电子科技大学出版社,2000:174-177.
[37]G M Martin,J P Farges et al.Compensation menchanisms in GaAs[J].Appl Phys,1980,51(5):2840-2851.
[2]G.M.Loubriel,F.J.Zutavern.and A.G.Baca et al.Photoconductive semiconductor switches[J].IEEE Trans.Plasma.Sci.,1997,25(2):124-130.
[3]G.M.Loubriel,F.J.Zutavern.Photoconductive semiconductor switch experiment for pulse application [J].IEEE Tran.on electron device.1990,37(12):2472-2477.
[4]Prather,W.D.Baum,C.E.Lehr,J.M.O'Loughlin,et al.Ultra-wideband source and antenna research [J].IEEE Trans.Plasma Science,2000,28.(5):1624-1630.
[5]Schoenberg,J.S.H.Burger,et al.Ultra-wideband source using gallium arsenide photoconductive semiconductor switches[J].IEEE Trans.Plasma Science,1997,25(2):327-334.
[6]Weiss M.D.,Crites M.H.,et al.Time-domain optical sampling of switched-mode microwave amplifiers and multipliers[J].IEEE Trans.Microwave Theory and Techniques,1999,47(12):2599-2604.
[7]S.Jayaraman,C.H.Lee.Observation of two-photo conductivity in GaAs with nanosecond and picosecond light pulse[J].Appl.Phys.Lett,1972,20(5):392-395.
[8]D.H.Auston.Picosecone opoelectronic swithing and gating in sillicon[J].Appl.Phys.Lett,1975,26(2):101-103.
[9]C.H.Lee et al.Picosecond optoelectronic switching in GaAs[J].Appl.Phys.Lett,1977,30(3):84-86.
[10]W.C.Nunnally,R.B.Hammond.80MW photoconductor power switches[J].Appl.Phys.Lett,1984,44(3):980-982.
[11]G.M.Loubriel,et al.Towards Pulsed Power Uses for Photoconductive Semiconductor Switches:Closing Switches[J].6~(th)IEEE Pulsed Power Conf.1987,145-148.
[12]S.D.Thibaut.Optically Activated Switching Ⅱ[J].PROC.SPIE,1992,1632(4):167-176.
[13]R.A.Fork,et al.Optical probe technique for avalanching photoconductors[C].Proc.8~(th)IEEE Pulsed Power Conference,1991:29-32.
[14]F.J.Zutavern,et al.Measurement of filament velocity and reduced triggering energy[J].Opticalluy Activated Switching Ⅳ,Proc.SPIE.1994,2343(8):21-31.
[15]J.M.Yee,et al.Modeling the effect of deep impurity ionization on GaAs photoconductive switches [J].Proc.SPIE Optically Activated Switching Ⅱ,1962,1632(5):21-28.
[16]W.T.White,et al.Modeling GaAs high-voltage subnanosecond photoconductive switches in one spatial dimension[J].IEEE Trans.Electron Devices,1990,37(12):2532-2541.
[17]R.P.Brinkmann,et al.Analysis of time-dependent current transport in an optically controlled Cu-compensated GaAs switch[J].Proc.SPIE Optically Activated Switching Ⅱ,1992,1633(7):262-273.
[18]H.Zhao,et al.Avalanche injection model for the lock-on effect in Ⅲ-Ⅴ power photoconductive Switches[J].J.Appl.Phys.1993,73(4):1807-1812.
[19]Shi Wei.Optically activated charge domain model for high-gain GaAs Photoconductive Switches [J].Chinese Journal of Semiconductors,2001,22(12):1481-1485.
[20]黄裕年.用光导半导体开关产生高功率微波[J].半导体光电,1998,19(2):101-106.
[21]D.H.Auston.Picosecond optoelectronic switching and gating in silicon [J].Appl.Phys.Lett,1975,26(6):101-103.
[22]C.H.Lee.Picosecond photoconductivity and its applications[J].IEEE Trans.J.Quantum Electronics,1981,17(2):2098-2107.
[23]C.H.Lee.Picosecond Optoelectronic Devices[C].Academic Press,New York,1984:126-129.
[24]G.M.Loubriel,et al.Towards pulsed power uses for Photoconductive Semiconductor Switches:Closing Switches[C].6~(th)IEEE Pulsed Power Conf.,1987:145-148.
[25]龚仁喜,张义门,石顺祥,张同意.高压GaAs光导开关的锁定及延迟效应机理分析[J].光学学报,2001,12(11):1372-1376.
[26]G M Martin,et al.Compensation mechanisms in GaAs[J].J Appl Phys,1980,51(5):2480-2852.
[27]R.A.Morrow.Model of EL2 formation in GaAs[J].Appl Phys,1991,70(11):6782-6787.
[28]W C Michel.Temperature dependence of the persistent photocurrent in czochralski gallium arsenide [J].Phys Rev,1990,B41(17):12086-12091.
[29]杨瑞霞.半绝缘LECGaAs中主要缺陷特性及其对材料和器件性能影响的研究[D].西安:西安交通大学,1998.
[30]王季陶,刘明登著.半导体材料[M].北京:高等教育出版社,1990:427-498.
[31]J Lagowski et al..Origin of 0.82eV electron trap in GaAs and tis annihilation by shallow donors[J].Appl Phys Lett,1982,40(4):342-344.
[32]赵会娟,牛憨笨.光导开关锁定机理的理论分析[J].光子学报,1997,26(1):61-65.
[33]杨瑞霞等.非掺杂半绝缘LEC GaAs的光电流谱[J].光谱学与光谱分析,1999,19(1):22-24.
[34]刘力锋.热处理对非掺杂半绝缘LEC GaAs本征缺陷及电特性影响的研究[D].河北:河北工业大学,2002.
[35]徐波等.EL2光淬灭过程中光电导增强现象原因新探[J].半导体学报,1994,15(5):322-328.
[36]谢孟贤,刘诺.化合物半导体材料与期间[D].成都:电子科技大学出版社,2000:174-177.
[37]G M Martin,J P Farges et al.Compensation menchanisms in GaAs[J].Appl Phys,1980,51(5):2840-2851.