Single event effects in circuit-hardened SiGe HBT logic at gigabit per second data rates

Abstract

This attempt at circuit level single event effects (SEE) hardening of SiGe HBT logic provides the first reported indication of the level of sensitivity in this important technology. Characterization over data rate up to 3 Gbps and over a broad range of heavy ion LET's provides important clues to upset mechanisms and implications for upset rate predictions. We augment ion test data with pulsed laser SEE testing to indicate the sensitive targets within the circuit and to provide insights into the upset mechanism(s).

An SEU hardening approach for high-speed SiGe HBT digital logic

“…Circuit A is the unhardened version of the D flip-flop used in the shift registers tested in [2]. The transistor level circuit is shown in Fig.…”

“…SEU sensitivity in SiGe HBT digital logic, as it is for any bipolar logic, depends on the circuit implementation, and hence one can in principle alter the circuit configuration in order to minimize SEU sensitivity. Previously, a comparison of SEU response in multiple SiGe HBT digital logic circuits indicated that cross-coupling at the transistor level in the storage cell negates any moderate SEU immunity achieved through circuit-level hardening using the current-shared hardening (CSH) [1] technique [2]. In this work, we propose an implementation of D flip-flop digital logic with a new circuit architecture featuring limited transistor-level decoupling in the storage cell and compare its predicted SEU response with three other circuit architectures.…”

Single Event Upset Mechanisms for Low-Energy-Deposition Events in SiGe HBTs

“…The angles used for simulation correspond to the angles used in broadbeam testing [13][14][15]. The "Effective LET" from Fig.…”

“…• A patterned subcollector (n for npn, p for pnp) on a doped substrate SiGe HBTs have been found to be quite tolerant to total ionizing dose (the amount of trapped charge accumulated over time found typically in the oxides and oxide interfaces of the device) and displacement effects (the result of lattice defects typically attributed to non-ionizing nuclear scattering reactions) [5][6][7][8][9][10][11], but are vulnerable to SEU [12][13][14][15][16]. [16].…”

“…SiGe HBTs have also been shown to be resistant to various types of ionizing radiation effects, making them a compelling candidates for space applications [4 -11]. Unfortunately, this technology is susceptible to SEU as seen, for example, in [12][13][14][15][16]. Space applications employing these circuits will require detailed analysis of the SEU susceptibility.…”