Hanbin Ying

Physical Differences in Hot Carrier Degradation of Oxide Interfaces in Complementary (n-p-n+p-n-p) SiGe HBTs

This paper examines the fundamental reliability differences between n-p-n and p-n-p SiGe HBTs. The device profile, hot carrier transport, and oxide interface differences between the two device types are explored in detail as they relate to device reliability. After careful analysis under identical electrical stress conditions for n-p-n and p-n-p, the differences in activation energies for the damage of the oxide interfaces of the two devices is determined to be the primary cause for accelerated degradation seen in p-n-p SiGe HBTs. An analytical model has been adapted for simulating these aging differences between p-n-p and n-p-n devices. This paper has significant implications for predicting the degradation of complementary SiGe HBTs and even engineering future generations with well-matched n-p-n and p-n-p device-level reliability.

Operation of SiGe HBTs Down to 70 mK

We present the first measurement results of a highly scaled, 90-nm silicon-germanium heterojunction bipolar transistor (SiGe HBT) operating at cryogenic temperatures as low as 70 mK. The SiGe HBT exhibits a transistor-like behavior down to 70 mK, but below 40 K, the transconductance suggests the presence of nonequilibrium transport mechanisms. Despite the non-ideal base current at cryogenic temperatures, a dc current gain (β) > 1 is achieved for IC > 1 nA, suggesting that ultralow-power low-noise amplifiers should be viable. Exposure of the SiGe HBT to strong magnetic fields (±14 T) is also presented to help understand the nature of the non-ideal

On the potential of using SiGe HBTs on SOI to support emerging applications up to 300°C

For the first time, the high temperature (to 300°C) DC and AC performance of a > 100 GHz f_T/f_max SiGe HBTs on thick-film SOI are investigated for their potential use in emerging energy sector, automotive, and aerospace applications. Metrics such as current gain (β_F), BV_CEO, M-1, f_T, f_max are extracted from 24°C to 300°C and compared with a bulk SiGe HBT platform. The results demonstrate that while there are degradation to key device metrics at high temperatures, the devices are still usable over a wide temperature range. Additionally, while SOI is known for its high thermal resistance, it is demonstrated that the device is constrained by electrical effects rather than thermal effects at higher temperatures, which should therefore yield acceptable reliability.

Single-Event Effects in High-Frequency Linear Amplifiers: Experiment and Analysis

The single-event transient (SET) response of two different silicon-germanium (SiGe) X-band (8–12 GHz) low noise amplifier (LNA) topologies is fully investigated in this paper. The two LNAs were designed and implemented in 130nm SiGe HBT BiCMOS process technology. Two-photon absorption (TPA) laser pulses were utilized to induce transients within various devices in these LNAs. Impulse response theory is identified as a useful tool for predicting the settling behavior of the LNAs subjected to heavy ion strikes. Comprehensive device and circuit level modeling and simulations were performed to accurately simulate the behavior of the circuits under ion strikes. The simulations agree well with TPA measurements. The simulation, modeling and analysis presented in this paper can be applied for any other circuit topologies for SET modeling and prediction.

Single-Event Effects in a Millimeter-Wave Receiver Front-End Implemented in 90 nm, 300 GHz SiGe HBT Technology

The single-event transient (SET) response of a W-band (75–110 GHz) radar receiver front-end is investigated in this paper. A new technique to facilitate the SET testing of the high frequency transceivers is proposed and demonstrated experimentally. The entire radar receiver front-end, including the high frequency signal sources and modulators, were designed and fully integrated in 90 nm 300 GHz SiGe process technology (Global Foundries SiGe 9HP). Two-photon absorption (TPA) laser pulses were utilized to induce transient currents in different devices in various circuit blocks. The study shows how short transient pulses from the high frequency tuned circuits are propagated throughout the receiver and are broadened while passing through low-pass filters present at supply nodes and the low-pass filter following the down-conversion mixer, thus affecting the digital data at the output of the receiver. The proposed methodology allows the study of the effect of SETs on the recovered digital data at the output of the high frequency receivers, thus allowing bit error rate calculations. Comprehensive device and circuit level simulations were also performed, and a close agreement between the measurement results and simulation data was demonstrated. To the authors’ best knowledge, this is the first study of SET on full receiver at millimeter-wave (mmW) frequencies.

Modeling of high-current damage in SiGe HBTs under pulsed stress

High-current pulsed stress measurements are performed on SiGe HBTs to characterize the damage behavior and create a comprehensive physics-based TCAD damage model for Auger-induced hot-carrier damage. The Auger hot-carrier generation is decoupled from classical mixed-mode damage and annealing on the output plane by using pulsed stress conditions to modulate the self-heating within the device under stress. The physics of high-current degradation is analyzed, and a temperature dependent degradation model is presented. This model is the first of its kind in both the CMOS and bipolar communities and solves a significant portion of the puzzle for predictive modeling of SiGe HBT safe-operating-area (SOA) and reliability.