Sub-pixel response of double-SOI pixel sensors for X-ray astronomy
Sub-pixel response of double-SOI pixel sensors for X-ray astronomy
复制标题
X 射线天文学双 SOI 像素传感器的亚像素响应
DOI：
10.1088/1748-0221/14/10/c10023
复制
发表时间：
2019
影响因子：
1.3
通讯作者：
et al.
中科院分区：
文献类型：
--
作者：
Koichi Hagino;Ayaki Takeda;et al.
我们一直在为未来的天体物理卫星开发称为XRPIX的X射线绝缘体上硅（SOI）像素传感器。XRPIX是一种单片有源像素传感器，由高电阻率Si传感器、薄SiO2绝缘体和利用SOI技术的CMOS像素电路组成。由于XRPIX能够进行事件驱动读出，因此它可以实现大于10 μs的高定时分辨率，通过采用反符合技术实现低背景观测。XRPIX开发中的主要问题之一是传感器层和电路层之间的电干扰，这会导致像素边界处的检测效率不均匀。为了减小这种干扰，我们引入了一种双SOI（D-SOI）结构，在SOI结构的绝缘层上增加了一层薄Si层（中间Si）。在该结构中，中间Si层用作电屏蔽以解耦传感器层和电路层。我们在KEK测量了具有D-SOI结构的XRPIX的探测器响应。我们用4 μm针孔准直的X射线束照射器件，以6 μm的间距扫描器件，即1/6的像素尺寸。本文介绍了D-SOI传感器探测效率均匀性的改善，并讨论了详细的X射线响应及其物理根源。
We have been developing the X-ray silicon-on-insulator (SOI) pixel sensor called XRPIX for future astrophysical satellites. XRPIX is a monolithic active pixel sensor consisting of a high-resistivity Si sensor, thin SiO 2 insulator, and CMOS pixel circuits that utilize SOI technology. Since XRPIX is capable of event-driven readouts, it can achieve high timing resolution greater than∼ 10 μs, which enables low background observation by adopting the anti-coincidence technique. One of the major issues in the development of XRPIX is the electrical interference between the sensor layer and circuit layer, which causes nonuniform detection efficiency at the pixel boundaries. In order to reduce the interference, we introduce a Double-SOI (D-SOI) structure, in which a thin Si layer (middle Si) is added to the insulator layer of the SOI structure. In this structure, the middle Si layer works as an electrical shield to decouple the sensor layer and circuit layer. We measured the detector response of the XRPIX with D-SOI structure at KEK. We irradiated the X-ray beam collimated with 4 μmϕ pinhole, and scanned the device with 6 μm pitch, which is 1/6 of the pixel size. In this paper, we present the improvement in the uniformity of the detection efficiency in D-SOI sensors, and discuss the detailed X-ray response and its physical origins.