An Analytical Model for Distributed Capacitance in Up-Down Series Stacked Inductors
IEEE TRANSACTIONS ON ELECTRON DEVICES
Authors: Tayenjam, Sobhana; Vanukuru, Venkata; Sundaram, Kumaravel
Abstract
Up-down series stacked inductors (UDSSIs) are known to have higher self-resonant frequency (SRF) when compared to standard series stacked inductors (SSSIs). In this article, a physics-based distributed capacitance model is presented to accurately estimate the inter-layer parasitic capacitance in both these configurations. Based on our analytical formulations, it is revealed that the total capacitance reduces substantially with increasing spiral turns in UDSSI, which is in turn responsible for increased SRF and inductor figure of merit (FOM). The importance of substrate resistivity and interlayer dielectric thickness in further improved inductor FOM with UDSSI configuration is also demonstrated. Prototype inductors using SSSI and UDSSI configurations are fabricated in 0.35-mu m BiCMOS technology. The measured results showed a 70% improvement in SRF with UDSSI structure while achieving inductance, quality factor, and FOM values of 31.54 nH, 12.34, and 4.4, respectively.
Upgrade Plan of the KOMAC Proton Linac for the Atmospheric Radiation Test on Semiconductor Devices
JOURNAL OF THE KOREAN PHYSICAL SOCIETY
Authors: Kim, Han-Sung; Kwon, Hyeok-Jung; Lee, Seung-Hyun; Dang, Jeong-Jeung; Lee, Pilsoo; Yoon, Sang-Pil; Cho, Yong-Sub
Abstract
At the Korea Multi-purpose Accelerator Complex (KOMAC), a 100-MeV high-power proton linac has been used for proton-beam irradiation services for various applications and research programs, including material science, bio-medical science, semiconductor applications, as well as nuclear physics and basic science, since commissioning of the machine in 2013. Recently, demands for fast neutrons from users in the semiconductor industries are increasing to test the semiconductor device SER (soft error rate) or SEE (single event effect). At present, we provide pilot services to users with pulsed white-spectrum neutrons (max. neutron energy similar to 100 MeV) generated at the beam dump, which is made of copper. However, the neutron energy should be increased at least to 200 MeV to meet international standards such as ISO26262 or JEDEC89A. For the upgrade of the linac energy to 200 MeV, we conducted a preliminary design study, including superconducting radio-frequency (SRF) based linac structure, a neutron generation target and a neutron utilization facility. The upgrade plan for the KOMAC linac, along with the preliminary results of the design study on the superconducting linac and neutron generation facility, will be given in this paper.