目前市面上的短波長紅外光(SWIR)或中波長紅外光(MWIR)波段的光偵測
器主要皆以 InGaAs、HgCdSe 等材料製作，其成本較為昂貴且無法直接生長於
矽基板上的問題。而 IV 族的鍺錫合金相較於上述兩者材料能夠與矽製成整合，
且為非毒性材料成本也較低，所以近期也成為了熱門的研究。然而，生長一個
高錫含量的鍺錫薄膜也面臨許多的挑戰，如高溫下表面容易產生錫偏析、錫難
以固溶於鍺薄膜中等，所以錫含量難以提升。
這項實驗使用了自製的電漿輔助化學氣相沉積系統，並以四氯化鍺及四氯
化錫作為前驅物，透過四氯化鍺蒸氣及四氯化錫蒸氣和氫原子反應於低溫下(約
100℃)，在矽基板上尋找適合生長高錫含量、高平整度非晶鍺錫薄膜的參數條
件，以及優化鍍膜步驟使其能夠形成鏡面般(Mirror – like)而非霧面(Foggy)的表
面。接著，嘗試藉由掃描式連續光雷射退火處理使其形成單晶鍺錫薄膜，並以
拉曼光普確認其結晶品質，於雷射掃描速度 0.3mm/s 及輔助器加熱溫度 300℃
下，以及在有二氧化矽作為覆蓋層用以提升雷射作用溫度，雷射掃描速度為
3mm/s 及輔助器加熱溫度 300℃下，皆能夠由拉曼光譜看到結晶的峰值出現，
然而結晶性尚未達到良好的品質，卻因為薄膜內含有殘留的氫氣尚未脫附，加
熱時會造成起泡現象導致薄膜破裂，因而被限制住無法繼續提高加熱作用的溫
度來提升結晶性，故必須尋找較高的生長溫度條件，防止氫氣的殘留。
於是本研究將近一步發展使用電漿侷限檔板的方法，於反應腔體前後兩端
加入實心開孔玻璃圓柱，圓孔大小設計為能使氣體通過，但不足以使電子產生
加速撞擊來產生電漿的直徑 5mm 大小，因此形成一個介電質侷限住電漿，以防
止前端進氣口區域消耗過多的四氯化錫前驅物。於此條件下，能夠以較高的溫
度生長鍺錫薄膜，再適當的參數下直接形成單晶且錫含量為 9%的鍺錫薄膜，滿
足能夠用以製作光偵測器的條件。

Currently, the short-wavelength infrared (SWIR) or mid-wavelength infrared (MWIR) photodetectors on the market are mainly made of InGaAs, HgCdSe and other materials, which are expensive and cannot be grown directly on silicon substrates.
Compared with the above two materials, the Group IV germanium-tin alloy can be integrated with silicon, and it is a non-toxic material with lower cost, so it has become popular research recently. However, growing a germanium-tin thin film with a high Sn content also face many challenges, such as the ease of occurrence of Sn segregation at
high temperature, the low bulk solubility of Sn in Ge, etc., so it is difficult to increase the Sn content.
In this work, a home-made plasma-enhanced chemical vapor deposition system was used, and germanium tetrachloride and tin tetrachloride were used as precursors, germanium tetrachloride vapor and tin tetrachloride vapor were reacted with hydrogen atoms at low temperature (About 100℃). Finding the parameter conditions suitable for the growth of high Sn content and high flatness amorphous germanium-tin thin film on silicon substrate and optimize the deposition steps to form a mirror-like surface rather than a foggy surface. Then, try to transform amorphous germanium-tin thin film into
monocrystalline by the scanning of CW laser annealing treatment. Raman spectroscopyand XRD measurements were used to investigate crystallinity. Under the laser scanning speed of 0.3mm/s and the auxiliary heating temperature of 300℃ by heater ; using silicon dioxide as a covering layer to increase the laser action temperature, the laser scanning speed is 3mm/s and the auxiliary heating temperature is 300℃, both of these two conditions can saw the peak showing the crystalline of germanium-tin thin film, but with low crystalline quality. Due to the formation and spallation of blisters occurred, it is limited and cannot continue to increase the heating temperature to improve the crystallinity, so it is necessary to find a better solution. High growth temperature conditions to prevent hydrogen residue.
Therefore, this study will further develop the method of using plasma confinement. Perforated solid cylindrical glass are added to the front and rear ends of the reaction chamber. The diameter of the circular holes is designed in 5mm, allow the gas to pass through but not enough to accelerate the electrons to generate plasma. Thus, forming a
dielectric to confine the plasma to prevent excessive consumption of the tin tetrachloride precursor in the front area. Under this condition, a germanium-tin thin film can be grown at a relatively high temperature, and then a monocrystalline germaniumtin film with a tin content of 9% can be directly formed under appropriate parameters,
which satisfies the conditions for making a photodetector.

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