Fabrication of large dual-polarized multichroic TES bolometer arrays for CMB measurements with the SPT-3G camera. (11th August 2015)

• Record Type: Journal Article
• Authors: Posada, C M; Ade, P A R; Ahmed, Z; Arnold, K; Austermann, J E; Bender, A N; Bleem, L E; Benson, B A; Byrum, K; Carlstrom, J E; Chang, C L; Cho, H M; Ciocys, S T; Cliche, J F; Crawford, T M; Cukierman, A; Czaplewski, D; Ding, J; Divan, R; de Haan, T; Dobbs, M A; Dutcher, D; Everett, W; Gilbert, A; Halverson, N W; Harrington, N L; Hattori, K; Henning, J W; Hilton, G C; Holzapfel, W L; Hubmayr, J; Irwin, K D; Jeong, O; Keisler, R; Kubik, D; Kuo, C L; Lee, A T; Leitch, E M; Lendinez, S; Meyer, S S; Miller, C S; Montgomery, J; Myers, M; Nadolski, A; Natoli, T; Nguyen, H; Novosad, V; Padin, S; Pan, Z; Pearson, J; Ruhl, J E; Saliwanchik, B R; Smecher, G; Sayre, J T; Shirokoff, E; Stan, L; Stark, A A; Sobrin, J; Story, K; Suzuki, A; Thompson, K L; Tucker, C; Vanderlinde, K; Vieira, J D; Wang, G; Whitehorn, N; Yefremenko, V; Yoon, K W; Ziegler, K E;
• Is Part Of: Superconductor science & technology. Volume 28:Number 9(2015:Sep.)
• Publication Date: 2015-08-11
• Subjects: bolometers -- TES detectors -- multichroic sensors -- CMB -- polarimetry -- microfabrication -- low loss microstrip; Superconductivity -- Periodicals; Superconductors -- Periodicals; 537.623
• DOI: 10.1088/0953-2048/28/9/094002
• Languages: English
• ISSNs: 0953-2048

Abstract

Abstract: This work presents the procedures used at Argonne National Laboratory to fabricate large arrays of multichroic transition-edge sensor (TES) bolometers for cosmic microwave background (CMB) measurements. These detectors will be assembled into the focal plane for the SPT-3G camera, the third generation CMB camera to be installed in the South Pole Telescope. The complete SPT-3G camera will have approximately 2690 pixels, for a total of 16 140 TES bolometric detectors. Each pixel is comprised of a broad-band sinuous antenna coupled to a Nb microstrip line. In-line filters are used to define the different bands before the millimeter-wavelength signal is fed to the respective Ti/Au TES bolometers. There are six TES bolometer detectors per pixel, which allow for measurements of three band-passes (95, 150 and 220 GHz) and two polarizations. The steps involved in the monolithic fabrication of these detector arrays are presented here in detail. Patterns are defined using a combination of stepper and contact lithography. The misalignment between layers is kept below 200 nm. The overall fabrication involves a total of 16 processes, including reactive and magnetron sputtering, reactive ion etching, inductively coupled plasma etching and chemical etching.