Developing a mass-production model of large-area Si(Li) detectors with high operating temperatures

Abstract

This study presents a fabrication process for lithium-drifted silicon (Si(Li)) detectors that, compared to previous methods, allows for mass production at a higher yield, while providing a large sensitive area and low leakage currents at relatively high temperatures. This design, developed for the unique requirements of the General Antiparticle Spectrometer (GAPS) experiment, has an overall diameter of 10 cm, with ~9 cm of active area segmented into 8 readout strips, and an overall thickness of 2.5 mm, with $\gtrsim$2.2 mm ($\gtrsim$90%) sensitive thickness. An energy resolution $\lesssim$4 keV full-width at half-maximum (FWHM) for 20-100 keV X-rays is required at the operating temperature ~-40C, which is far above the liquid nitrogen temperatures conventionally used to achieve fine energy resolution. High-yield production is also required for GAPS, which consists of $\gtrsim$1000 detectors. Our specially-developed Si crystal and custom methods of Li evaporation, diffusion and drifting allow for a thick, large-area and uniform sensitive layer. We find that retaining a thin undrifted layer on the p-side of the detector drastically reduces the leakage current, which is a dominant component of the energy resolution at these temperatures. A guard-ring structure and optimal etching of the detector surface are also confirmed to suppress the leakage current. We report on the mass production of these detectors that is ongoing now, and demonstrate it is capable of delivering a high yield of ~90%.

arXiv comment28 pages, 11 figures, submitted in 6/13/2019; re-submitted in 8/23/2019;

References in corpus (16)

• Secondary antiprotons and propagation of cosmic rays in the Galaxy and heliosphere
• Antiprotons in cosmic rays from neutralino annihilation
• Novel dark matter constraints from antiprotons in the light of AMS-02
• Antideuterons as a Signature of Supersymmetric Dark Matter
• Flux of light antimatter nuclei near earth, induced by Cosmic Rays in the Galaxy and in the atmosphere
• Antideuteron Sensitivity for the GAPS Experiment
• Review of the theoretical and experimental status of dark matter identification with cosmic-ray antideuterons
• Prospects to verify a possible dark matter hint in cosmic antiprotons with antideuterons and antihelium
• Search for the Charged Higgs Boson in the Decays of Top Quark Pairs in the $e\tau$ and $\mu \tau$ Channels at $\sqrt{s}$=1.8 TeV
• Study of the process $e^{+}{e}^{-}\to {\pi }^{+}{\pi }^{-}\eta$ using initial state radiation
• Potential for Precision Measurement of Low-Energy Antiprotons with GAPS for Dark Matter and Primordial Black Hole Physics
• Measurement of the p-pbar -> Wgamma + X cross section at sqrt(s) = 1.96 TeV and WWgamma anomalous coupling limits
• Fabrication of low-cost, large-area prototype Si(Li) detectors for the GAPS experiment
• A systematic study on the cosmic ray antiproton flux
• Large-area Si(Li) detectors for X-ray spectrometry and particle tracking in the GAPS experiment
• Large-area Si(Li) Detectors for X-ray Spectrometry and Particle Tracking for the GAPS Experiment

Cited by in corpus (11)

• Cosmic-ray Antinuclei as Messengers of New Physics: Status and Outlook for the New Decade
• Cosmic antihelium-3 nuclei sensitivity of the GAPS experiment
• Large-area Si(Li) detectors for X-ray spectrometry and particle tracking in the GAPS experiment
• Passivation of Si(Li) detectors operated above cryogenic temperatures for space-based applications
• Sensitivity of the GAPS Experiment to Low-energy Cosmic-ray Antiprotons
• Statistical investigation of the large-area Si(Li) detectors mass-produced for the GAPS experiment
• The antinucleus annihilation reconstruction algorithm of the GAPS experiment
• Large-scale detector testing for the GAPS Si(Li) Tracker
• Large-area Si(Li) Detectors for X-ray Spectrometry and Particle Tracking for the GAPS Experiment
• New Technologies for Discovery
• GAPS: Searching for Dark Matter using Antinuclei in Cosmic Rays