Development of pixel sensors based on SOI technology.

SOI是一种半导体技术，其中低电阻率硅在通常硅晶片上方的SiO2绝缘体层上形成。该技术使CMOS电路比普通的体CMOS工艺更好。如果将高电阻率硅用于晶片，并且在晶片中感应的信号电荷可以由SiO2层上方的CMOS电路处理，则可以生产单片辐射传感器。由于深亚微米技术，可以生产适用于粒子追踪和X射线成像的20 prax 20 pm等精细像素传感器。在这项研究中，我们与日本主要SOI代工厂OM Electric合作。我们开发了单片像素传感器。同时，还进行了TCAD模拟、抗辐射性、高性能模拟电路等基础研究。2006年活动：采用SOI技术加工了几个测试芯片和128 x128像素传感器。我们证实了该设备的功能和对脉冲激光和最小电离粒子的敏感性。成像的能力也得到了证明。同时，在器件和半导体仿真工具TCAD中对注入能量进行了基础研究，真正实现了击穿电压的提高。测定了辐射耐受性。我们确认SOI CMOS电路可以在30 M rad γ射线辐照和10^<15>/cm ^2中子通量以上工作。2007活动：受2007年开发成果的鼓舞，设计并加工了一个专用于Super KEKB项目升级探测器的原型像素传感器。初步测试表明，传感器部分的静态特性（I-V特性）是令人满意的。动力性能测试正在进行中，测试结果将于近期公布。

SOI is a semiconductor technology, where the low-resistivity silicon is developed on a Si02 insulator layer above usual silicon wafers. The technology enables Thster CMOS circuit than normal bulk CMOS process. If high-resistivity silicon is used for the wafer and the signal charge induced in the wafer can be processed by the CMOS circuit above the Si02 layer a monolithic radiation sensor can be produced. Because of the deep sub-micron technology, afine pixel sensor such as 20 prax 20 pm, that is suitable for particle traeking and X ray imaging, can be produced.In this study, we collaborated with OM Electric, a major SOI foundry in Japan., we developed a monolithic pixel sensor. In parallel, basic studies such as a TCAD simulation, radiation hardness, high performance analogue circuit were done.2006 Activities: Several test chips and 128x128 pixel sensor was processed with SOI technology. We confirmed the functionality of the device and sensitivity to pulsed laser light and minimum-ionizing particles. The capability of imaging is also demonstrated. In parallel, basic study of implantation energy was done in TCAD (device and semiconductor simulation tool) and improvement of break-down voltage is really achieved. The radiation tolerance was measured. We confirmed the SOI CMOS circuit can be operated above 30 M rad γ ray irradiation and 10^<15>/cm^2neuiron flux.2007 Activities: Encouraged by the result of 2007 developments, a prototype pixel sensor dedicated for for the upgrade detector for the Super KEKB project is designed and processed. The preliminary measurement shows the static properties of sensor part (I-V characteristics) is satisfactory. The test of dynamic properties is still in progress and the result will be published soon.