Design and fabrication of high-speed wide-bandwidth pin/HBT OEIC for 1550nm optical fiber communication.
| Autor: | Hsiao-Wen Chung, 鍾孝文 |
|---|---|
| Rok vydání: | 2006 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 94 The high-speed, wide-bandwidth optoelectronic integrated circuits (OEIC’s) have been studied in this thesis with three different topologies. The presented OEIC consists of an InGaAs photodetector (PD) and a one-stage common-base InP/InGaAs HBT transimpedance amplifier (CB-TIA) for 1550 nm optical communication system. One of fabricated OEIC’s achieves excellent results and thus be accepted to appear on IEEE Photonic Technology Letter. First of all, the top illuminated InGaAs p-i-n PD and InP/InGaAs heterojunction bipolar transistor (HBT) are integrated by using monolithic technology. The absorption layer of the p-i-n PD is formed from the 5000Å-thick InGaAs collector of the HBT on the same wafer. A CB-TIA is used to implement the p-i-n/HBT integration for OEIC. The measurement results show the 85 GHz cut-off frequency of the HBT with the emitter size of 4×12 μm2. The p-i-n PD exhibits a responsivity of ~0.22 A/W. The bandwidth of p-i-n PD and OEIC are 14.5 GHz and 14 GHz, respectively, by heterodyne beating measurement. The performance of OEIC is significantly limited by p-i-n PD, thus an evanescently coupled photodetector is proposed to increase the bandwidth. The evanescently coupled photodetector (ECPD) and CB-TIA were designed and fabricated. The absorption layer thickness of p-i-n PD is reduced to 3000 Å to improve the response time. Due to the evanescently coupled structure, the responsivity of ECPD is improved and discussed in detail in chapter 2 and chapter 4, respectively. The measurement results show the cut-off frequency of HBT is 110 GHz after de-embedded calibration. The responsivity of ECPD is improved to 0.3 A/W. The electrical bandwidth of ECPD and OEIC are 30 and 37 GHz, respectively. The 37 GHz bandwidth of fabricated OEIC is published on IEEE PTL. In addition, the flip-chip technology is applied to the evanescently coupled OEIC to save InP substrate. The ECPD and HBT were fabricated on InP wafer, and the passive components such as DC pads, RF pads, connection wires, and resistance were fabricated on the S.I. GaAs substrate. By using the flip-chip binding, the InP wafer has been saved ~91 %, and flip-chip bound OEIC demonstrates a -3dB bandwidth of 34 GHz. In appendix, the principle, merits, and design flow of distributed amplifier (DA) are demonstrated. This 2 stage structure DA was fabricated by 0.15μm pHEMT process provided by WIN semiconductor corp. The measurement results show a transimpedance gain of 40.3 dBΩ with a -3 dB bandwidth of 36 GHz. The wide band performance demonstrates that the DA is very suitable for high speed optical communication system. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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