Displacement damage degradation of ion-induced charge in Si pin photodiode Shinobu Onoda a,b, * , Toshio Hirao b , Jamie Stuart Laird b , Hidenobu Mori a , Hisayoshi Itoh b , Takeshi Wakasa a , Tsuyoshi Okamoto a , Yoshiharu Koizumi a a Tokai University, Graduate School of Engineering, 1117 Kitakaname, Hiratsuka, Kanagawa 259-1292, Japan b Severe Environment Materials Laboratory, Department of Materials Development, Japan Atomic Energy Research Institute, 1233 Watanuki, Takasaki, Gunma 370-1292, Japan Abstract Photonic devices operating in space must exhibit high-radiation hardness due to prolonged exposure to high-energy radiation fields. The device performance can be influenced by both the transient effect of electron–hole plasma gen- eration due to stopping of high-energy particles, and the accumulated effect of damage introduced by a flux of particles. The complex relationship between the two is an increasingly important area of research. Here we investigate charge collection characteristics of in situ ion beam induced damaged samples by measuring single event transient currents induced by heavy ions. Results from this study suggest that the ion-induced charge degradation can be predicted for any ion species and energy using the concept of non-ionizing energy loss and displacement damage dose. Ó 2003 Elsevier Science B.V. All rights reserved. Keywords: Displacement damage effect; Single event effect; Non-ionizing energy loss; Collected charge 1. Introduction Semiconductor devices operated in radiation environment such as the space must exhibit high- radiation hardness due to exposure to high-energy radiation. When a high-energy particle traverses a device, a dense electron–hole pair plasma is gen- erated which can lead to temporary or permanent failures known as single event effects (SEE). An- other common occurrence is radiation damage due to displacement or dislodging of atoms from their normal sites. Since any device encounters both these effects in its lifetime, an investigation of the complex relationship between the two is an im- portant issue. To date however, there have been few reports on the influence of ion-induced damage on the single event response of a device [1]. In this paper we present charge collection results obtained from single event transient currents measured on in situ ion damaged devices. The data for a range of ions and energies are compared using the concept of non-ionizing energy loss (NIEL). 2. Experiment Heavy ions used in this study were 15 MeV O and10MeVAufromthe3MVTandemaccelerator * Corresponding author. Address: Course of Applied Sci- ence, Graduate School of Engineering, Tokai University, 1117 Kitakaname, Hiratsuka, Kanagawa 259-1292, Japan. Tel.: +81- 27-346-9324; fax: +81-27-346-9687. E-mail address: onoda@taka.jeaeri.go.jp (S. Onoda). 0168-583X/03/$ - see front matter Ó 2003 Elsevier Science B.V. All rights reserved. doi:10.1016/S0168-583X(03)00790-0 Nuclear Instruments and Methods in Physics Research B 206 (2003) 444–447 www.elsevier.com/locate/nimb