标题： 带电粒子检测性能的CMOS像素传感器，采用高电阻率外延层的0.18微米工艺生产 显示英文标题

标题： Charged particle detection performances of CMOS pixel sensors produced in a 0.18 um process with a high resistivity epitaxial layer

摘要： ALICE实验在CERN的设备将在2017/18年进行升级，这是在大型强子对撞机（LHC）第二长期停机期间进行的。 这次升级的主要动机是将物理研究范围扩展到低横向动量的奇夸克和底夸克粒子。 这需要显著提高ALICE内跟踪系统（ITS）的空间分辨率和数据率能力。 为了达到这个目标，新的ITS将配备50微米厚的CMOS像素传感器（CPS），覆盖探测器的3个最内层或全部7个层。 为IPHC（斯特拉斯堡）的ITS升级开发的CPS源自用于RHIC的STAR-PXL的MIMOSA 28传感器，在0.35微米CMOS工艺中实现。 为了满足ITS升级在读出速度和辐射耐受性方面的要求，应采用特征尺寸较小且具有高电阻率外延层的CMOS工艺。 在这方面，TowerJazz 0.18微米CMOS工艺的带电粒子检测性能和辐射硬度通过第一个原型芯片MIMOSA 32进行了研究。 在CERN-SPS使用120 GeV/c的负π介子进行的束流测试允许测量非辐照芯片的信噪比（SNR），其范围根据像素设计在22到32之间。 辐照了1 MRad和10^13 n_eq/cm^2综合剂量的芯片在冷却温度从15 C到30 C变化时，测得的SNR范围在11到23之间。这些SNR值被测得在辐照前和辐照后分别产生高于99.5%和98%的粒子检测效率。 这些令人满意的结果使得TowerJazz 0.18微米CMOS工艺能够被验证用于ALICE ITS的升级。 显示英文摘要

摘要： The apparatus of the ALICE experiment at CERN will be upgraded in 2017/18 during the second long shutdown of the LHC (LS2). A major motivation for this upgrade is to extend the physics reach for charmed and beauty particles down to low transverse momenta. This requires a substantial improvement of the spatial resolution and the data rate capability of the ALICE Inner Tracking System (ITS). To achieve this goal, the new ITS will be equipped with 50 um thin CMOS Pixel Sensors (CPS) covering either the 3 innermost layers or all the 7 layers of the detector. The CPS being developed for the ITS upgrade at IPHC (Strasbourg) is derived from the MIMOSA 28 sensor realised for the STAR-PXL at RHIC in a 0.35 um CMOS process. In order to satisfy the ITS upgrade requirements in terms of readout speed and radiation tolerance, a CMOS process with a reduced feature size and a high resistivity epitaxial layer should be exploited. In this respect, the charged particle detection performance and radiation hardness of the TowerJazz 0.18 um CMOS process were studied with the help of the first prototype chip MIMOSA 32. The beam tests performed with negative pions of 120 GeV/c at the CERN-SPS allowed to measure a signal-to-noise ratio (SNR) for the non-irradiated chip in the range between 22 and 32 depending on the pixel design. The chip irradiated with the combined dose of 1 MRad and 10^13 n_eq/cm^2 was observed to yield a SNR ranging between 11 and 23 for coolant temperatures varying from 15 C to 30 C. These SNR values were measured to result in particle detection efficiencies above 99.5% and 98% before and after irradiation respectively. These satisfactory results allow to validate the TowerJazz 0.18 um CMOS process for the ALICE ITS upgrade.