公开(公告)号：US5077593A

公开(公告)日：1991-12-31

申请号：US457613

申请日：1989-12-27

申请人： Robert N. Sato ,  Chan-Shin Wu ,  Cheng P. Wen

发明人： Robert N. Sato ,  Chan-Shin Wu ,  Cheng P. Wen

IPC分类号： H01L31/0352

CPC分类号： B82Y20/00 ,  H01L31/035236

摘要： A multiquantum well superlattice photodetector for detecting long wavelength infrared radiation in which dark current is reduced by a blocking layer. The tunneling component of the dark current in a multiquantum well photodetector is substantially eliminated by placing a blocking layer at one end of the superlattice. The blocking layer has a potential energy barrier having a height at the same level of the barrier layers of the superlattice. The thickness of the blocking layer is substantially greater than the barrier layers of the superlattice to prevent charge carriers which tunnel through the superlattice from reaching the ohmic contact.

摘要翻译： 一种用于检测长波长红外辐射的多量子阱超晶格光电探测器，其中暗电流被阻挡层减小。 通过在超晶格的一端放置阻挡层，基本上消除了多量子阱光电探测器中的暗电流的隧穿分量。 阻挡层具有在超晶格的阻挡层的相同水平处具有高度的势垒。 阻挡层的厚度基本上大于超晶格的阻挡层，以防止穿过超晶格的电荷载体达到欧姆接触。

公开(公告)号：US5198682A

公开(公告)日：1993-03-30

申请号：US792070

申请日：1991-11-12

申请人： Chan-Shin Wu ,  Cheng P. Wen

发明人： Chan-Shin Wu ,  Cheng P. Wen

IPC分类号： H01L31/0352

CPC分类号： B82Y20/00 ,  H01L31/035236

摘要： A multiple quantum well superlattice radiation detector is compositionally graded to establish an internal electric field within the superlattice that allows the device to operate with a reduced or zero externally applied bias voltage. The compositional grading can be implemented by grading the doping levels of successive quantum wells or the relative proportions of elements in successive barrier layers of the superlattice, or by a combination of the two. If a tunneling current blocking layer is employed, it can also be compositionally graded to inhibit a substantial increase in the blocking layer's barrier energy level near a charge carrier collector on the other side of the blocking layer from the superlattice. The charge carrier collector can itself be provided with a graded dopant concentration near the blocking layer to inhibit reverse bias voltage breakdown in the blocking layer.

摘要翻译： 多量子阱超晶格辐射检测器被组成分级，以在超晶格内建立内部电场，允许器件以减小的或零的外部施加的偏置电压工作。 组成分级可以通过对连续量子阱的掺杂水平进行分级或超晶格的连续势垒层中元素的相对比例，或通过两者的组合来实现。 如果使用隧道电流阻挡层，则其也可以被组成分级，以阻止阻挡层的另一侧与超晶格附近的电荷载流子收集器附近的阻挡层势垒能级的显着增加。 电荷载流子收集器本身可以在阻挡层附近设置渐变掺杂剂浓度，以阻止阻挡层中的反向偏置电压击穿。

公开(公告)号：US5563423A

公开(公告)日：1996-10-08

申请号：US431382

申请日：1995-04-28

申请人： Chan-Shin Wu ,  Robert N. Sato ,  Cheng P. Wen

发明人： Chan-Shin Wu ,  Robert N. Sato ,  Cheng P. Wen

IPC分类号： H01L31/0352 ,  H01L31/0304 ,  H01L31/101

CPC分类号： B82Y20/00 ,  H01L31/035236

摘要： An improved multiquantum well superlattice photodetector (10) for detecting long wavelength infrared radiation. Electron transport in a first excited energy state is enhanced in barrier layers (20) of the superlattice (16) by lowering the potential energy barriers of the barrier layers (20) to a predetermined level below the first excited energy state. The tunneling component of the dark current in a multiquantum well photodetector (10) may be substantially eliminated by placing a blocking layer (22) at one end of the superlattice (16). The thickness of the blocking layer (22) is also substantially greater than that of the barrier layers (20) of the superlattice (16) to prevent charge carriers which tunnel through the superlattice (16) from reaching the collector contact. The blocking layer (22) also has a potential energy barrier having a height at a level higher than that of the barrier layers (20) of the superlattice (16).

摘要翻译： 一种用于检测长波长红外辐射的改进的多量子阱超晶格光电探测器（10）。 通过将阻挡层（20）的势能垒降低到低于第一激发能量状态的预定水平，在超晶格（16）的势垒层（20）中增强了第一激发能态的电子传输。 通过在超晶格（16）的一端放置阻挡层（22），可以基本上消除多量子阱光电探测器（10）中的暗电流的隧穿分量。 阻挡层（22）的厚度也基本上大于超晶格（16）的阻挡层（20）的厚度，以防止穿过超晶格（16）的电荷载体到达集电极触点。 阻挡层（22）还具有高度高于超晶格（16）的阻挡层（20）的高度的势垒。

公开(公告)号：US5296720A

公开(公告)日：1994-03-22

申请号：US792535

申请日：1991-11-17

申请人： Cheng P. Wen ,  Chan-Shin Wu

发明人： Cheng P. Wen ,  Chan-Shin Wu

IPC分类号： H01L31/0352 ,  H01L27/14 ,  H01L31/00

CPC分类号： B82Y20/00 ,  H01L31/035236

摘要： A multiple quantum well (MQW) radiation sensor distinguishes radiation within a desired bandwidth, particularly long wavelength infrared radiation (LWIR), from background high intensity noise radiation that excites majority-minority charge carrier pairs. A minority charge carrier collector is provided at one end of the MQW, and the flow of minority charge carriers to the collector is sensed. The minority charge carrier flow provides an indication of the majority charge carrier flow that is attributable to the noise radiation rather than to radiation within the desired bandwidth, and can thus be used to provide a corrected indication of the desired bandwidth radiation.

摘要翻译： 多量子阱（MQW）辐射传感器将辐射从背景高强度噪声辐射中区分出期望带宽，特别是长波长红外辐射（LWIR），激发多数少数电荷载体对。 在MQW的一端设置少数电荷载流子收集器，并且感测到少数电荷载流子到集电器的流动。 少数电荷载流子提供可归因于噪声辐射的多数电荷载流子流的指示，而不是期望带宽内的辐射，并且因此可用于提供所需带宽辐射的校正指示。

公开(公告)号：US5572049A

公开(公告)日：1996-11-05

申请号：US422110

申请日：1995-04-14

申请人： Cheng P. Wen ,  Chan-Shin Wu ,  Cheng-Keng Pao ,  David B. Rensch ,  William E. Stanchina

发明人： Cheng P. Wen ,  Chan-Shin Wu ,  Cheng-Keng Pao ,  David B. Rensch ,  William E. Stanchina

IPC分类号： H01L29/08 ,  H01L29/737 ,  H01L31/0328 ,  H01L31/0336

CPC分类号： H01L29/7371 ,  H01L29/0821

摘要： A multi-layer collector heterojunction transistor (10) provides for high power, high efficiency transistor amplifier operation, especially in the RF (radio frequency) range of operation. A larger band gap first collector layer (12), approximately 15% of the active collector region (11) thickness, is provided at the base-collector junction (13). A smaller band gap second collector layer (14) forms the remainder of the active collector region (11). The multi-layer collector structure provides higher reverse bias breakdown voltage and higher carrier mobility during relevant portions of the output signal swing. A lower saturation voltage limit, or "knee" voltage, is provided at the operating points where linear operating regions transition to saturation operating regions as depicted in the output voltage-current (I-V) characteristic curves. The magnitude of the output signal swing of an amplifier may be increased, providing higher power amplification with greater power efficiency. The power supply voltage for the amplifier may be increased, providing for the use of a smaller, lighter power supply.

摘要翻译： 多层收集器异质结晶体管（10）提供高功率，高效率的晶体管放大器操作，特别是在RF（射频）操作范围内。 在基极 - 集电极结（13）处提供大约15％的有源集电极区域（11）厚度的较大的带隙第一集电极层（12）。 较小的带隙第二集电极层（14）形成有源集电极区域（11）的剩余部分。 多层收集器结构在输出信号摆幅的相关部分期间提供更高的反向偏压击穿电压和较高的载流子迁移率。 在输出电压 - 电流（I-V）特性曲线中描绘的线性工作区域转变到饱和工作区域的工作点处，提供较低的饱和电压限制或“拐点”电压。 可以增加放大器的输出信号摆幅的大小，以更高的功率效率提供更高的功率放大。 可以增加放大器的电源电压，从而提供更小，更轻的电源的使用。

公开(公告)号：US5352904A

公开(公告)日：1994-10-04

申请号：US792502

申请日：1991-11-21

申请人： Cheng P. Wen ,  Chan-Shin Wu

发明人： Cheng P. Wen ,  Chan-Shin Wu

IPC分类号： H01L31/0352 ,  H01L27/14 ,  H01L31/00

CPC分类号： H01L31/035236 ,  B82Y20/00

摘要： A multiple quantum well (MQW) radiation sensor eliminates tunneling current from the photoactivated current that provides an indication of incident radiation, and yet preserves a substantial bias voltage across the superlattice, by fabricating an intermediate contact layer between the superlattice and a tunneling blocking layer. Using the intermediate contact layer to apply a bias voltage across the superlattice but not the blocking layer, the photoexcited current flow through the intermediate contact and blocking layers is taken as an indication of the incident radiation. The width of the intermediate contact layer and the barrier energy height of the blocking layer relative to that of the superlattice barrier layers are selected to enable a substantial photoexcited current flow across the blocking layer. The thickness of the intermediate contact layer is preferably not more than about 1 photoexcited charge carrier mean-free path length, while the blocking layer's barrier energy height is preferably at least about 1 phonon energy level below that of the superlattice barrier layers.

摘要翻译： 多量子阱（MQW）辐射传感器消除了提供入射辐射指示的光活化电流的隧道电流，并且通过在超晶格和隧道阻挡层之间制造中间接触层，保持超晶格上的实质偏压。 使用中间接触层在超晶格上施加偏置电压而不是阻挡层，通过中间接触和阻挡层的光电流流动被作为入射辐射的指示。 选择中间接触层的宽度和阻挡层相对于超晶格势垒层的阻挡能量高度，以使能够穿过阻挡层的实质的光电流流动。 中间接触层的厚度优选为不大于约1个光激发电荷载体平均自由路径长度，而阻挡层的势垒能高度优选为低于超晶格势垒层的能级的至少约1个声子能级。

公开(公告)号：US06534783B1

公开(公告)日：2003-03-18

申请号：US09819186

申请日：1993-11-15

申请人： Chan-Shin Wu ,  Cheng P. Wen

发明人： Chan-Shin Wu ,  Cheng P. Wen

IPC分类号： H01L2906

CPC分类号： B82Y20/00 ,  H01L31/035236

摘要： A radiation detector, particularly suited for the detection of long wavelength infrared radiation, employs a plurality of multiple quantum well (MQW) superlattices in a unitary stack. The superlattices are electrically connected in parallel, and current outputs are obtained from the parallel connection as an indication of the incident radiation. Electrical contact layers are provided on the opposite sides of each superlattice, with adjacent superlattices sharing a common contact layer. The number of quantum well/barrier layer periods per superlattice is preferably reduced to about 20-30 divided by the number of superlattices in the stack, as compared to a single-superlattice detector with about 20-30 periods. This allows a common bias voltage applied to the superlattices to be similarly reduced by a factor approximately equal to the number of superlattices in the stack. The reduction in superlattice thickness and bias voltage yields a higher external quantum efficiency, improved signal-to-noise ratio and lower power consumption. The detector can be implemented either as a single color system with similar superlattices, or as a multi-color system in which each superlattice is tuned to a different radiation waveband.

摘要翻译： 特别适用于长波长红外辐射检测的辐射探测器在整体叠层中采用多个多量子阱（MQW）超晶格。 超晶格并联电连接，电流输出作为入射辐射的指示从并联获得。 电接触层设置在每个超晶格的相对侧上，相邻的超晶格共享共同的接触层。 与具有约20-30个周期的单超晶格检测器相比，每个超晶格的量子阱/势垒层周期的数量优选地减小到约20-30除以堆叠中的超晶格数。 这允许施加到超晶格的公共偏置电压类似地减小大约等于堆叠中的超晶格数量的因子。 超晶格厚度和偏置电压的降低产生更高的外部量子效率，改善的信噪比和更低的功耗。 检测器可以被实现为具有类似超晶格的单色系统，或者作为多色系统，其中每个超晶格被调谐到不同的辐射波段。

公开(公告)号：US5272356A

公开(公告)日：1993-12-21

申请号：US792519

申请日：1991-11-12

申请人： Cheng P. Wen ,  Chan-Shin Wu

发明人： Cheng P. Wen ,  Chan-Shin Wu

IPC分类号： H01L27/146 ,  H01L27/14 ,  H01L31/00

CPC分类号： B82Y20/00 ,  H01L27/146

摘要： A multiple quantum well (MQW) superlattice photodetector, is surmounted by a slab of transparent material having an angled surface that extends upward and away from the photodetector, such that incident radiation which is initially normal to the superlattice undergoes total internal reflection at the angled surface and is reflected onto the detector at a substantially non-normal angle. This off-normal angle allows the radiation to be partially absorbed by the detector. A reflection grating is preferably formed on the opposite side of the detector to redirect received radiation back through the MQW superlattice at an altered angle, such that remaining radiation can be absorbed by the detector during the second pass. The detector is formed upon a substrate, with the slab, substrate and quantum wells all preferably formed from the same type of material. Multiple detectors may be formed in an array upon a common substrate, with a slab providing a common reflective surface for the overall array.

摘要翻译： 多量子阱（MQW）超晶格光电探测器由具有向上和远离光电检测器的倾斜表面的透明材料板覆盖，使得最初垂直于超晶格的入射辐射在成角度的表面处经历全内反射 并以基本上非正常角度反射到检测器上。 该偏离角度允许辐射被检测器部分地吸收。 优选地，在检测器的相对侧上形成反射光栅，以将接收到的辐射以改变的角度重新通过MQW超晶格反射，使得在第二次通过期间可以由检测器吸收剩余的辐射。 检测器形成在衬底上，板，衬底和量子阱都优选由相同类型的材料形成。 多个检测器可以阵列形成在公共基底上，其中平板为整个阵列提供共同的反射表面。

公开(公告)号：US5026148A

公开(公告)日：1991-06-25

申请号：US457207

申请日：1989-12-26

申请人： Cheng P. Wen ,  Chan-Shin Wu ,  Robert N. Sato

发明人： Cheng P. Wen ,  Chan-Shin Wu ,  Robert N. Sato

IPC分类号： H01L31/0232 ,  H01L31/0236 ,  H01L31/0352

CPC分类号： B82Y20/00 ,  H01L31/0232 ,  H01L31/0236 ,  H01L31/035236 ,  Y02E10/50

摘要： A multiple quantum well photodetector structure has superlattice which absorbs radiation polarized non-parallel to the superlattice during a first pass. Non-absorbed radiation polarized parallel to the superlattice is reflected back into the superlattice at a cross-angle to its incident angle, with its polarization shifted to a substantially non-parallel angle to the superlattice. At least part of this radiation is absorbed during its second pass through the superlattice, thereby increasing the efficiency of the device. An optical back grating is used to perform the cross-angle reflection, and a front grating may also be used to shift an incoming beam which is initially normal to the superlattice to an angle at which part of the beam is absorbed. The front grating is at a cross-angle to the back grating to enable a cross-angular shift by the back grating.

摘要翻译： 多量子阱光电探测器结构具有超晶格，其在第一次通过期间吸收在超晶格上非平行偏振的辐射。 与超晶格平行偏振的非吸收辐射被反射回超晶格，与其入射角成十角角，其偏振偏移到与超晶格基本不平行的角度。 这种辐射的至少一部分在其穿过超晶格的第二次通过期间被吸收，从而提高了器件的效率。 光学背光栅用于执行交叉角反射，并且前光栅也可以用于将最初正常于超晶格的入射光束移动到波束的一部分被吸收的角度。 前光栅与后光栅交叉成角度，以便通过后光栅进行交叉角移动。