在矽基板上製造鍺p-i-n以及砷化鎵金屬-半導體-金屬光偵測器

Abstract

近幾年來，由於光纖通訊市場之需求，操作在1300nm到1550nm波段(近紅外光)之光偵測器有很廣泛的應用價值，同時，將光與電元件整合在同一基板上是非常熱門的研究。 在本論文中，矽鍺緩衝層被拿來當作差排介面阻擋層以成長高品質的鍺以及砷化鎵薄膜在矽基板上並在薄膜成長之後對薄膜做材料分析，最後我們成功地在矽基板上製作了鍺p-i-n以及砷化鎵金屬-半導體-金屬光偵測器同時並量測其光電性質。 對鍺p-i-n光偵測器而言，在-1伏以及-3伏特時其暗電流分別為2.6x10-06 A [0.1625 A/cm2 ]以及4.85x10-06 (安培) [0.303 A/cm2] ，同時其響應度為0.107 A/W 以及0.565 A/W 在1310nm波段。 而對砷化鎵金屬-半導體-金屬光偵測器而言,在-1伏以及-3伏特時其暗電流分別為6.92x10-9 A [1.081x10-4A/cm2]以及2.01x10-8 A [3.14x10-3 A/cm2] ，同時其響應度為0.0217 A/W 以及0.0401 A/W 在850nm波段。經過與純砷化鎵金屬-半導體-金屬光偵測器比較，可發現兩者有幾乎相同之響應度但砷化鎵金屬-半導體-金屬光偵測器有比純砷化鎵金屬-半導體-金屬光偵測器有較大一點之暗電流，這暗示在矽基板上砷化鎵薄膜之品質和純砷化鎵差不多。

In recent years, the demand for photodetector operating at wavelength, of 1300 nm and 1550 nm (near infrared light) is growing rapidly, due to the need for optical fiber communication systems. Also, the integration of the optical and electrical devices on a chip is very of great interest. In this thesis, the SiGe buffer layer was used to serve as the interface blocking layer and the high quality Ge and GaAs layers were grown on Si substrate. After epitaxial growth, Ge and GaAs films were analyzed. Finally the Ge p-i-n and the GaAs metal-semiconductor-metal (M-S-M) photodetectors was successful fabricated on Si substrate and the performance was measured. For the fabricated Ge p-i-n photodetector, the dark currents were 2.6x10-06 A [0.1625 A/cm2] and 4.85x10-06 A [0.303 A/cm2] and the responsivities were 0.107 A/W and 0.565 A/W respectively when biased under -1V and-3V at 1310 nm wavelength. For GaAs M-S-M photodetector on Si substrate, the dark currents were 6.92x10-9 A [1.081x10-4A/cm2] and 2.01x10-8 A [3.14x10-3 A/cm2] and the responsivities were 0.0217 A/W and 0.0401 A/W respectively when biased at -1V and-3V at 850 nm wavelength. After comparing the results with the pure GaAs photodetector, it was found that the responsivities of the two structures were almost the same but the dark current of the GaAs/Ge/SiGe/Si structure MSM photodetector was only a little larger than the pure GaAs structure MSM photodetector. It implies that the quality of the GaAs film on Si substrate is almost the same as the pure GaAs film.