Substrate Effects on Charge Carrier Transport Properties of Single‐Crystal CVD Diamonds and an 8mm Square Radiation Energy Spectrometer

• Published in: Physica status solidi. A, Applications and materials science Vol. 215; no. 22
• Main Authors: Hirano, Shintaro, Kaneko, Junichi H, Hanada, Takanori, Ito, Shogo, Shimaoka, Takehiro, Shimmyo, Hiroaki, Tsubota, Masakatsu, Chayahara, Akiyoshi, Mokuno, Yoshiaki, Umezawa, Hitoshi
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 01.11.2018
• Subjects: Alpha particles; Alpha rays; Carrier transport; Charge efficiency; Charge transport; Chemical vapor deposition; Crystal growth; Current carriers; Diamonds; Electrons; Energy resolution; Organic chemistry; Single crystals; Substrates
• ISSN: 1862-6300; 1862-6319
• DOI: 10.1002/pssa.201800333

In an effort to enlarge a sensitive area of a diamond radiation energy spectrometer, a self‐standing chemical vapor deposition (CVD) single crystal is grown on an 8‐mm‐square “general grade” CVD single‐crystal diamond substrate fabricated by Element Six Ltd. The growth conditions that achieved a μτ product of 3 × 10−4 cm2 V−1 for holes in a CVD single‐crystal diamond grown on a high‐pressure and high‐temperature (HP/HT) type IIa single‐crystal diamond substrate elsewhere are adopted. The charge collection efficiency (CCE) of 99.9% for both charge carriers, and 0.39% and 0.5% of energy resolution for holes and electrons are achieved using 5.486 MeV alpha particles. Uniformity of the energy resolution is sufficient for the use of a radiation energy spectrometer. However, μτ products of (5.0 ± 0.4) × 10−5 and (1.8 ± 0.2) × 10−5 cm2 V−1 for holes and electrons are obtained, respectively. These values are approximately one order of magnitude smaller than the μτ products of the CVD single crystal grown on a HP/HT type IIa diamond substrate using the same growth conditions.