dorsal/arxiv
View SchemaHybrid-Contact Planar HPGe Process Vehicle Toward Ring-Contact Designs
| Authors | Kunming Dong, Dongming Mei, Shasika Panamaldeniya, Anupama Karki, Patrick Burns, Sanjay Bhataarai |
|---|---|
| Categories | |
| ArXiv ID | 2601.08934vv1 |
| URL | https://arxiv.org/abs/2601.08934 |
| License | http://creativecommons.org/licenses/by/4.0/ |
Abstract
Rare-event searches including dark matter, coherent elastic neutrino--nucleus scattering (CE$\nu$NS), and neutrinoless double-beta decay (0$\nu\beta\beta$) require high-purity germanium (HPGe) detectors with ultralow noise, stable backgrounds, and electrode geometries that can scale to larger single-crystal masses. Ring-contact (ring-and-groove) designs address scalability by shaping the electric field to preserve low-capacitance readout, but their nonplanar topology motivates a lithium-contact process that is compatible with conformal deposition and robust high-voltage operation. As a process demonstration toward future ring-contact prototypes, we fabricate and characterize a hybrid-contact planar HPGe device, KL01. Here, ``hybrid'' denotes an $n^{+}$ contact formed by an in-house lithium-suspension paint followed by controlled thermal diffusion, combined with an AJA-developed a-Ge/Al $p^{+}$ contact and a-Ge sidewall passivation. At 77~K the device exhibits pA-scale leakage current under kV bias, a depletion plateau near $V_{\mathrm{dep}}\approx 1300$~V, and energy resolutions of 1.57~keV FWHM at 59.5~keV and 2.57~keV FWHM at 662~keV. These results validate the compatibility of the paint-and-diffuse lithium process with thin-film a-Ge/Al contacts and establish a practical fabrication workflow to be extended to ring-and-groove electrodes for next-generation rare-event HPGe modules.
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"date_created": "2026-02-17T05:53:19.775000Z",
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"abstract": "Rare-event searches including dark matter, coherent elastic neutrino--nucleus scattering (CE$\\nu$NS), and neutrinoless double-beta decay (0$\\nu\\beta\\beta$) require high-purity germanium (HPGe) detectors with ultralow noise, stable backgrounds, and electrode geometries that can scale to larger single-crystal masses. Ring-contact (ring-and-groove) designs address scalability by shaping the electric field to preserve low-capacitance readout, but their nonplanar topology motivates a lithium-contact process that is compatible with conformal deposition and robust high-voltage operation. As a process demonstration toward future ring-contact prototypes, we fabricate and characterize a hybrid-contact planar HPGe device, KL01. Here, ``hybrid\u0027\u0027 denotes an $n^{+}$ contact formed by an in-house lithium-suspension paint followed by controlled thermal diffusion, combined with an AJA-developed a-Ge/Al $p^{+}$ contact and a-Ge sidewall passivation. At 77~K the device exhibits pA-scale leakage current under kV bias, a depletion plateau near $V_{\\mathrm{dep}}\\approx 1300$~V, and energy resolutions of 1.57~keV FWHM at 59.5~keV and 2.57~keV FWHM at 662~keV. These results validate the compatibility of the paint-and-diffuse lithium process with thin-film a-Ge/Al contacts and establish a practical fabrication workflow to be extended to ring-and-groove electrodes for next-generation rare-event HPGe modules.",
"arxiv_id": "2601.08934",
"authors": [
"Kunming Dong",
"Dongming Mei",
"Shasika Panamaldeniya",
"Anupama Karki",
"Patrick Burns",
"Sanjay Bhataarai"
],
"categories": [
"physics.ins-det",
"hep-ex",
"nucl-ex"
],
"license": "http://creativecommons.org/licenses/by/4.0/",
"title": "Hybrid-Contact Planar HPGe Process Vehicle Toward Ring-Contact Designs",
"url": "https://arxiv.org/abs/2601.08934",
"version": "v1"
},
"schema_id": "dorsal/arxiv",
"source": {
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"id": "arXiv Dataset",
"type": "Model",
"variant": "snapshot-2026-01-17",
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