High-performance GeSi/Ge multi-quantum well photodetector on a Ge-buffered Si substrate.

This work demonstrates a high-performance photodetector with a 4-cycle Ge0.86Si0.14/Ge multi-quantum well (MQW) structure grown by reduced pressure chemical vapor deposition techniques on a Ge-buffered Si (100) substrate. At -1 V bias, the dark current density of the fabricated PIN mesa devices is as low as 3 mA/cm2, and the optical responsivities are 0.51 and 0.17 A/W at 1310 and 1550 nm, respectively, corresponding to the cutoff wavelength of 1620 nm. At the same time, the device has good high-power performance and continuous repeatable light response. On the other hand, the temperature coefficient of resistance (TCR) of the device is as high as -5.18%/K, surpassing all commercial thermal detectors. These results indicate that the CMOS-compatible and low-cost Ge0.86Si0.14/Ge multilayer structure is promising for short-wave infrared and uncooled infrared imaging.

Interface Investigation on SiGe/Si Multilayer Structures: Influence of Different Epitaxial Process Conditions.

SiGe/Si multilayer is the core structure of the active area of gate-all-around field-effect transistors and semiconductor quantum computing devices. In this paper, high-quality SiGe/Si multilayers have been grown by a reduced-pressure chemical vapor deposition system. The effects of temperature, pressure, interface processing (dichlorosilane (SiH2Cl2, DCS) and hydrogen chloride (HCl)) on improving the transition thickness of SiGe to Si interfaces were investigated. The interface quality was characterized by transmission electron microscopy/atomic force microscopy/high-resolution X-ray diffraction methods. It was observed that limiting the migration of Ge atoms in the interface was critical for optimizing a sharp interface, and the addition of DCS was found to decrease the interface transition thickness. The change of the interfacial transition layer is not significant in the short treatment time of HCl. When the processing time of HCl is increased, the internal interface is optimized to a certain extent but the corresponding film thickness is also reduced. This study provides technical support for the acquisition of an abrupt interface and will have a very favorable influence on the performance improvement of miniaturized devices in the future.

A meta-analysis of clinical trials over regimens with or without cetuximab for advanced gastric cancer patients.

PURPOSE: To evaluate the efficiency and toxicity of treatment with or without cetuximab in patients with advanced gastric cancer (AGC). METHODS: Randomized phase III clinical trials (RCTs) on chemotherapy with or without cetuximab for AGC were searched in PUBMED and CNKI. A total of 874 patients were analyzed for their overall survival (OS), disease control rate (DCR), and toxicity. Reported hazard ratio (HR) with 95% CI from each study were used as the primary outcome measure. RESULTS: Three RCTs were detected on chemotherapy with or without cetuximab regimens for AGC. Chemotherapy plus cetuximab was not significantly advantageous over chemotherapy alone for OS rate and DCR odds ratio (OR) (OS: OR=0.89, 95% CI=0.50-1.56; DCR:OR=1.11, 95% CI=0.78-1.59). However, haematological toxicity and neutropenia were lower in the experimental group (chemotherapy plus cetuximab) than in the control group (chemotherapy alone) (OR=0.65, 95% CI=0.50-0.84). No evidence of publication bias was found in this study. CONCLUSION: Adding cetuximab to chemotherapy does not improve OS or DCR compared with chemotherapy alone. Cetuximab-containing combination chemotherapy can reduce the risk of neutropenia.