An overview is presented of total ionizing dose (TID) effects in MOS and bipolar devices from a historical perspective, focusing primarily on work presented at the annual IEEE Nuclear and Space Radiation Effects Conference (NSREC). From the founding of the IEEE NSREC in 1964 until ~1976, foundational work led to the discovery of TID effects in MOS devices, the characterization of basic charge transport and trapping processes in SiO2, and the development of the first generations of metal-gate radiation-hardened MOS technologies. From ~1977 until ~1985, significant progress was made in the understanding of critical defects and impurities that limit the radiation response of MOS devices. These include O vacancies in SiO2, dangling Si bonds at the Si/SiO2 interface, and hydrogen. In addition, radiation-hardened Si-gate CMOS technologies were developed. From ~1986 until ~1997, a significant focus was placed on understanding postirradiation effects in MOS devices and implementing hardness assurance test methods to qualify devices for use in space systems. Enhanced low-dose-rate sensitivity (ELDRS) was discovered and investigated in linear bipolar devices and integrated circuits. From ~1998 until the present, an increasing focus has been placed on theoretical studies enabled by rapidly advancing computational capabilities, modeling and simulation, effects in ultra-thin oxides and alternative dielectrics to SiO2, and in developing a comprehensive model of ELDRS.

Total Ionizing Dose Effects in MOS and Low-Dose-Rate-Sensitive Linear-Bipolar Devices

"Extreme environments" represents an important niche market for electronics and spans the operation of electronic components in surroundings lying outside the domain of conventional commercial, or even military, specifications. Such extreme environments would include, for instance, operation to very low temperatures (e.g., to 77 K or even 4.2 K), operation at very high temperatures (e.g., to 200/spl deg/C or even 300/spl deg/C), and operation in a radiation-rich environment (e.g., space). We argue that the unique bandgap-engineered features of silicon-germanium heterojunction bipolar transistors offer great potential to simultaneously satisfy all three extreme environment applications, potentially with little or no process modification, ultimately providing compelling cost advantages at the IC and system level.

On the Potential of SiGe HBTs for Extreme Environment Electronics

This expanded and thoroughly revised edition of Thomas H. Lee's acclaimed guide to the design of gigahertz RF integrated circuits features a completely new chapter on the principles of wireless systems. The chapters on low-noise amplifiers, oscillators and phase noise have been significantly expanded as well. The chapter on architectures now contains several examples of complete chip designs that bring together all the various theoretical and practical elements involved in producing a prototype chip. First Edition Hb (1998): 0-521-63061-4 First Edition Pb (1998); 0-521-63922-0

The Design of CMOS Radio-Frequency Integrated Circuits: RF CIRCUITS THROUGH THE AGES

Extremely compact resistive-feedback CMOS low-noise amplifiers (LNAs) are presented as a cost-effective alternative to multiple narrowband LNAs using high-Q inductors for multiband wireless applications. Limited linearity and high power consumption of the inductorless resistive-feedback LNAs are analyzed and circuit techniques are proposed to solve these issues. A 12-mW resistive-feedback LNA, based on current-reuse transconductance boosting is presented with a gain of 21 dB and a noise figure (NF) of 2.6 dB at 5 GHz. The LNA achieves an output third-order intercept point (IP3) of 12.3 dBm at 5 GHz by reducing loop-gain rolloff and by improving linearity of individual stages. The active die area of the LNA is only 0.012 mm2. A 9.2-mW tuned resistive-feedback LNA utilizing a single compact low-Q on-chip inductor is presented, showing an improved tradeoff between performance, power consumption, and die area. At 5.5 GHz, the fully integrated LNA achieves a measured gain of 24 dB, an NF of 2 dB, and an output IP3 of 21.5 dBm. The LNA draws 7.7 mA from the 1.2-V supply and has a 3-dB bandwidth of 3.94 GHz (4.04-7.98 GHz). The LNA occupies a die area of 0.022 mm2. Both LNAs are implemented in a 90-nm CMOS process and do not require any costly RF enhancement options.

Resistive-Feedback CMOS Low-Noise Amplifiers for Multiband Applications

Silicon-Germanium (SiGe) technology effectively merges the desirable attributes of conventional silicon-based CMOS manufacturing (high integration levels, at high yield and low cost) with the extreme levels of transistor performance attainable in classical III-V heterojunction bipolar transistors (HBTs). SiGe technology joins together on-die high-speed bandgap-engineered SiGe HBTs with conventional Si CMOS to form SiGe BiCMOS technology, including all the requisite RF passive elements and multi-level thick-Al metalization required for high-speed circuit design. Such an silicon-based integrated circuit technology platform presents designers with an ideal division of labor for realizing optimal solutions to many performance-constrained mixed-signal (analog + digital + RF) systems. The unique bandgap-engineered features of SiGe HBTs enable several key merits with respect to operation across a wide variety of so-called “extreme environments”, potentially with little or no process modification, ultimately providing compelling advantages at the circuit and system level, across a wide class of envisioned commercial and defense applications. Here we give an overview of this interesting field, focusing primarily on the intersection of SiGe HBTs, and circuits built from them, with radiation-intense environments such as space.

Radiation Effects in SiGe Technology

We present the first experimental results of the effects of 63 MeV proton irradiation on both the lateral and vertical scaling properties of SiGe HBT BiCMOS technology. Three distinct generations of (unhardened) SiGe technology are examined. The first generation SiGe HBTs experience very minor degradation in current gain at proton fluence as high as 2/spl times/10/sup 13/ p/cm/sup 2/. The second and third generations SiGe HBTs, however, show 60-70% degradation in current gain under similar conditions, suggesting that emitter-base spacer optimization may be required as the technology is scaled. Si nFETs from the first generation SiGe BiCMOS technology are only hard to about 40 krad equivalent gamma dose, and are limited by drain-to-source leakage along the shallow trench edge. The second generation Si nFETs, however, improve with scaling since the shallow trench is thinned, and can withstand up to 150 krad of equivalent dose.

The effects of proton irradiation on the lateral and vertical scaling of UHV/CVD SiGe HBT BiCMOS technology

We present results on the impact of proton irradiation on the dc and ac characteristics of third-generation, 0.12 /spl mu/m 185 GHz SiGe HBTs. Comparisons with prior technology generations are used to assess how the structural changes needed to enhance performance between second and third generation technology couple to the observed proton response. The results demonstrate that SiGe HBT technologies can successfully maintain their a Mrad-level total dose hardness, without intentional hardening, even when vertically-scaled in order to achieve unprecedented levels of transistor performance.

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Proton tolerance of third-generation, 0.12 /spl mu/m 185 GHz SiGe HBTs

We investigate the proton radiation tolerance of a 035 /spl mu/m SOI technology on UNIBOND material The radiation response is characterized by threshold-voltage shifts of the front-gate and back-gate transistors An increase of the front-gate threshold voltage is observed on the n-channel MOSFETs after irradiation and is attributed to radiation-induced interface states at the front-gate oxide/silicon interface A double g/sub m/ peak behavior is observed on the back-gate g/sub m/-V/sub GS/ curves for both n- and p-channel MOSFETs and is attributed to silicon/back-gate oxide interface traps with a delta-function-like distribution in the energy gap The results suggest this 035 /spl mu/m technology on UNIBOND material performs well in a proton-radiation environment

Proton radiation effects in 0.35 /spl mu/m partially depleted SOI MOSFETs fabricated on UNIBOND

We investigate the proton tolerance of fully depleted silicon-on-insulator (SOI) MOSFETs with H-gate and regular-gate structural configurations. For the front-gate characteristics, the H-gate does not show the edge leakage observed in the regular-gate transistor. An anomalous kink in the back-gate linear I/sub D/-V/sub GS/ characteristics of the fully depleted SOI nFETs has been observed at high radiation doses. This kink is attributed to charged traps generated in the bandgap at the buried oxide/silicon film interface during irradiation. Extensive two-dimensional simulations with MEDICI were used to understand the physical origin of this kink. We also report unusual self-annealing effects in the devices when they are cooled to liquid nitrogen temperature.

Anomalous radiation effects in fully depleted SOI MOSFETs fabricated on SIMOX

The paper presents the results of an investigation of the proton tolerance of the multiple-threshold voltage and multiple-breakdown voltage device design points contained in a 0.18 /spl mu/m system-on-a-chip CMOS technology. The radiation response of the CMOS devices having three different device design configurations are characterized and compared for equivalent gamma doses up to 300 krad(Si), using the threshold voltage, off-state leakage, and effective mobility to assess the dc performance. All three CMOS device configurations show a very slight degradation of threshold voltage and effective mobility with increasing dose. We also present for the first time the frequency response and S-parameters of these RF CMOS devices under proton radiation. The S-parameters and cut-off frequency show little degradation up to 300 krad(Si) total dose. These results suggest that the CMOS devices in this 0.18 /spl mu/m SoC CMOS technology are well-suited for RF circuit applications in an ionizing radiation environment without intentional total-dose hardening.

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Proton tolerance of multiple-threshold voltage and multiple-breakdown voltage CMOS device design points in a 0.18 /spl mu/m system-on-a-chip CMOS technology

Ying Li

Papers

The effects of proton irradiation on the lateral and vertical scaling of UHV/CVD SiGe HBT BiCMOS technology

Proton tolerance of third-generation, 0.12 /spl mu/m 185 GHz SiGe HBTs

Proton radiation effects in 0.35 /spl mu/m partially depleted SOI MOSFETs fabricated on UNIBOND

Anomalous radiation effects in fully depleted SOI MOSFETs fabricated on SIMOX

Proton tolerance of multiple-threshold voltage and multiple-breakdown voltage CMOS device design points in a 0.18 /spl mu/m system-on-a-chip CMOS technology