單光子崩潰二極體光計數與暗計數之時間特性

Abstract

在此論文中，我們量測了數種不同SPAD元件(TSMC 0.25μm高壓製程與 0.18μm製程)的二次崩潰與時基誤差特性。這兩種特性可以分別顯示元件暗計數與光計數在時間上的分佈，並且提供許多元件內載子行為的資訊。在二次崩潰量測方面，我們採用與傳統方法不同的量測方式，希望能提供另一種較為簡便的方法以得到同樣的資訊，我們稱之為timed pulse measurement。這種方法不需要讓元件搭配電路，而且可以用多種不同的模式進行量測，因此可以根據元件的特性選擇所使用的模式。根據量測結果，我們比較了各種量測模式的優劣，也評估了各元件的二次崩潰特性。另一方面，利用Ti:Sapphire飛秒雷射與TCSPC模組，我們以4ps的精準度量測了各元件的時基誤差。除了觀察其對元件偏壓的相關性外，我們也探討了雷射光點入射位置與元件大小對時基誤差的影響，由此證實時基誤差的成因。這些量測資訊可以作為往後元件設計重要的參考。最後，為了進一步探討元件中崩潰傳遞行為的時間特性，我們設計了一系列具有多個陰極的元件。這些元件除了可以用於崩潰傳遞研究之外，也很有潛力發展為位置敏感的光偵測器(position-sensitive photodetector)，是未來可行的一個研發方向。

In this work, the afterpulsing and timing jitter of several single-photon avalanche diodes (SPADs) of various structures and processes (TSMC 0.25μm High Voltage and 0.18μm) are measured. These two measurements can reveal the temporal characteristics of dark counts and photo-counts, respectively. They also provide information about the physical behavior of carriers in the devices. Regarding the measurement of afterpulsing, we take an approach different from the conventional one, with the intent to obtain the same outcome with a simpler experimental setup, which we call “timed pulse measurement”. In this method, quenching circuits are not required, and devices can be measured in several modes, from which the most suitable mode of measurement should be chosen considering the performance of the device of interest. According to the results, we compare the pros and cons of the modes and also evaluate the afterpulsing effects in each device. On the other hand, using a Ti:Sapphire femtosecond laser and a TCSPC module, we measure the timing jitter of the devices at 4ps resolution. In addition to observing the correlation of jitter value and the excess bias, we also examine the dependence on the position of the laser spot and on the device diameter, confirming some of the physical origins of timing jitter. The experimental data of both measurements can serve as a good reference for future modification on the device structures. Last of all, a group of devices with multiple cathodes are designed for further study of the temporal characteristics of breakdown propagation. Apart from enabling the study of breakdown propagation, these devices have great potential to be developed into position-sensitive detectors, opening a new direction for future research.