First tests of a novel radiation hard CMOS sensor process for Depleted Monolithic Active Pixel Sensors
First tests of a novel radiation hard CMOS sensor process for Depleted Monolithic Active Pixel Sensors
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DOI：
10.1088/1748-0221/12/06/p06008
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发表时间：
2017-06
影响因子：
1.3
通讯作者：
H. Pernegger;R. Bates;C. Buttar;M. Dalla;J. V. Hoorne;T. Kugathasan;D. Maneuski;L. Musa;P. Riedler;C. Riegel;C. Sbarra;D. Schaefer;E. J. Schioppa;W. Snoeys
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文献类型：
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作者：
H. Pernegger;R. Bates;C. Buttar;M. Dalla;J. V. Hoorne;T. Kugathasan;D. Maneuski;L. Musa;P. Riedler;C. Riegel;C. Sbarra;D. Schaefer;E. J. Schioppa;W. Snoeys
欧洲核子研究中心(CERN)高亮度大型强子对撞机(LHC)ATLAS[1]跟踪探测器的升级需要新的辐射硬硅传感器技术。单片cmos传感器的开发已经投入了大量的努力，但将传感节点的低电容与敏感层的完全耗尽结合起来一直是一个挑战。低电容带来低模拟功率。敏感层的耗尽导致信号电荷被足够快的漂移收集，以将命中与连续的束团交叉(在LHC上为25 ns)分开，并避免因陷阱而损失电荷。本文主要研究在爱丽丝内跟踪系统(ITS)升级框架下设计的原型传感器的电荷收集特性和探测效率[2]。原型采用标准TowerJazz 180 nm cmos成像仪工艺[3]和与代工厂合作开发的该工艺的创新改进工艺制造，旨在完全耗尽敏感的外延层并增强对非电离能量损失的耐受性。利用放射源、聚焦X射线束和测试束对标准工艺和改进工艺制造的传感器在辐照前后进行了表征。与标准工艺制造的传感器相反，改进工艺的传感器即使在剂量达到1015neq/cm2后仍保持完全功能，这是未来ATLAS内跟踪器(ITK)[4]中外层像素层的预期Niel辐射通量。
The upgrade of the ATLAS [1] tracking detector for the High-Luminosity Large Hadron Collider (LHC) at CERN requires novel radiation hard silicon sensor technologies. Significant effort has been put into the development of monolithic CMOS sensors but it has been a challenge to combine a low capacitance of the sensing node with full depletion of the sensitive layer. Low capacitance brings low analog power. Depletion of the sensitive layer causes the signal charge to be collected by drift sufficiently fast to separate hits from consecutive bunch crossings (25 ns at the LHC) and to avoid losing the charge by trapping. This paper focuses on the characterization of charge collection properties and detection efficiency of prototype sensors originally designed in the framework of the ALICE Inner Tracking System (ITS) upgrade [2]. The prototypes are fabricated both in the standard TowerJazz 180nm CMOS imager process [3] and in an innovative modification of this process developed in collaboration with the foundry, aimed to fully deplete the sensitive epitaxial layer and enhance the tolerance to non-ionizing energy loss. Sensors fabricated in standard and modified process variants were characterized using radioactive sources, focused X-ray beam and test beams before and after irradiation. Contrary to sensors manufactured in the standard process, sensors from the modified process remain fully functional even after a dose of 1015neq/cm2, which is the the expected NIEL radiation fluence for the outer pixel layers in the future ATLAS Inner Tracker (ITk) [4].