The Effects of Proton and X-Ray Irradiation on the DC and AC Performance of Complementary (npn + pnp) SiGe HBTs on Thick-Film SOI

Abstract

The impact of 63.3 MeV proton and 10 keV x-ray irradiation on the DC and AC performance of complementary ( + ) SiGe HBTs on thick-film SOI is investigated. Proton and x-ray induced changes in the forward and inverse Gummel characteristics, the output characteristics, and avalanche multiplication are reported for both npn and pnp SiGe HBTs, at both room temperature (300 K) and at cryogenic temperatures (down to 30 K). Comparison of room temperature and cryogenic data suggests interface trap formation at two distinct physical locations in the transistors. Experimental data and calibrated TCAD simulations are used to compare the radiation response of both thick-film SOI devices and thin-film SOI SiGe HBTs.

Comparison of total dose effects on SiGe heterojunction bipolar transistors induced by different swift heavy ion irradiation

“…Ionization damages create some positive oxide trapped charges and interface states around the EB spacer oxide layer, which act as generation-recombination (G-R) centers and increase the base surface recombination current in the low V BE region. [12][13][14][15] Displacement damages are induced by the collision between incoming particles and atoms in the semiconductor lattice. When the swift heavy ion passes through the semiconductor material, the lattice atoms will deviate from their original position.…”

“…[1][2][3][4][5][6][7][8] The special device structure and unique band gap engineering in the base enable SiGe HBTs to have a wide temperature range capability and multi-Mrad total ionizing dose (TID) tolerance without hardening. [9][10][11][12][13] As a result, SiGe HBTs gain significant attention as a candidate in extreme environment applications, especially in radiation-rich space explorations. Therefore, it is essential to explore the irradiation characteristics and underlying damage mechanisms in SiGe HBTs and related circuits to find suitable hardening strategies for practical applications.…”

“…For bipolar transistors, ionization damages induce the interface states and positive oxide trapped charges around the emitter-base (EB) spacer oxide, leading to an increase of the base current and decrease of the current gain. [10][11][12] Typical radiation sources to assess ionization damages are 60 Co gamma ray, proton and electron.…”

Re-Examining TID Hardness Assurance Test Protocols for SiGe HBTs

“…Performed under the standard test procedure, virtually no degradation in collector current ( ) post-exposure [3], [4] is observed, whereas the base current ( ) typically shows a near slope leakage component in the base current. A typical pre-irradiation and post-irradiation Gummel characteristic is shown in Fig.…”

“…1 to illustrate. Many studies have been focused on the degradation of base current, since it affects common device figures-of-merit such as current and RF gain [4].…”