The HgCdTe electron avalanche photodiode
The HgCdTe electron avalanche photodiode
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DOI：
10.1117/12.565142
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发表时间：
2004-10
影响因子：
2.1
通讯作者：
James E. Beck;C. Wan;M. Kinch;J. Robinson;P. Mitra;R. Scritchfield;F. Ma;J. Campbell
中科院分区：
文献类型：
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作者：
James E. Beck;C. Wan;M. Kinch;J. Robinson;P. Mitra;R. Scritchfield;F. Ma;J. Campbell
短波红外 (SWIR) 至长波红外 (LWIR) HgCdTe 中的电子注入雪崩光电二极管显示出指示单个电离载流子增益过程的增益和过量噪声特性。结果是电子雪崩光电二极管 (EAPD) 具有“理想”APD 特性，包括近乎无噪声的增益。本文报告了在长波、中波和短波截止红外 Hg1−xCdxTe EAPD（10 µm、5 µm 和 2.2 µm）上获得的结果，该 EAPD 使用圆柱形“p-around-n”正面照明 n+/n-/p 几何结构，有利于电子注入增益区。这些器件的特点是具有均匀的指数增益电压特性，该特性与零的空穴与电子电离系数比 k=αh/αe 一致。在 MWIR EAPDS 中测量到的增益超过 1,000，没有任何雪崩击穿的迹象。中波红外 (MWIR) 和 SWIR EAPD 的过量噪声测量显示，在高增益下，增益独立的过量噪声系数的极限值小于 2。在 77 K 时，4.3 µm 截止器件显示接近 1,000 增益的过量噪声系数。在 77 K 的 MWIR APD 上测量的 10 ns 脉冲信号增益为 964 时，噪声等效输入为 7.5 个光子，这表明了该新器件的功能。 SWIR EAPD 在室温下的超额噪声系数虽然仍与 k=0 操作一致，但由于室温下预期的电子-声子相互作用，接近接近 2 的增益独立极限值。 k=0 操作可以通过 HgCdTe 的能带结构来解释。基于 HgCdTe 能带结构和散射模型的蒙特卡罗建模可预测测量的增益和过量噪声行为。
Electron injection avalanche photodiodes in short-wave infrared (SWIR) to long-wave infrared (LWIR) HgCdTe show gain and excess noise properties indicative of a single ionizing carrier gain process. The result is an electron avalanche photodiode (EAPD) with “ideal” APD characteristics including near noiseless gain. This paper reports results obtained on long-, mid-, and short-wave cutoff infrared Hg1−xCdxTe EAPDs (10 µm, 5 µm, and 2.2 µm) that use a cylindrical “p-around-n” front side illuminated n+/n-/p geometry that favors electron injection into the gain region. These devices are characterized by a uniform, exponential, gain voltage characteristic that is consistent with a hole-to-electron ionization coefficient ratio, k=αh/αe, of zero. Gains of greater than 1,000 have been measured in MWIR EAPDS without any sign of avalanche breakdown. Excess noise measurements on midwave infrared (MWIR) and SWIR EAPDs show a gain independent excess noise factor at high gains that has a limiting value less than 2. At 77 K, 4.3-µm cutoff devices show excess noise factors of close to unity out to gains of 1,000. A noise equivalent input of 7.5 photons at a 10-ns pulsed signal gain of 964 measured on an MWIR APD at 77 K provides an indication of the capability of this new device. The excess noise factor at room temperature on SWIR EAPDs, while still consistent with the k=0 operation, approaches a gain independent limiting value of just under 2 because of electron-phonon interactions expected at room temperature. The k=0 operation is explained by the band structure of the HgCdTe. Monte Carlo modeling based on the band structure and scattering models for HgCdTe predict the measured gain and excess noise behavior.