W.C. Jenkins

Worst case total dose radiation response of 0.35 /spl mu/m SOI CMOSFETs

Through experimental results and analysis by TSUPREM4/MEDICI simulations, the worst case back gate total dose bias condition is established for body tied SOI NMOSFETs. Utilizing the worst-case bias condition, a recently proposed model that describes the back n-channel threshold voltage shift as a function of total dose, TSUPREM4/MEDICI simulations, and circuit level SPICE simulations, a methodology to model post-rad standby current is developed and presented. This methodology requires the extraction of fundamental starting material/material preparation constants, and then can be utilized to examine post-rad stand-by current at the device and circuit level as function of total dose. Good agreement between experimental results and simulations is demonstrated.

Total dose radiation hard 0.35 /spl mu/m SOI CMOS technology

This paper presents the total dose radiation performance of 0.35 /spl mu/m SOI CMOS devices fabricated in a radiation hard full dose SIMOX technology. The radiation performance is characterized by transistor threshold voltage shifts, transistor array leakage currents, and 256 K SRAM standby currents as a function of total dose up to 10 Mrad(SiO/sub 2/). The worst case threshold voltage shifts of front channels are less than 60 mV for PMOS transistors at 1 Mrad(SiO/sub 2/) and less than 10 mV for NMOS transistors. No significant radiation induced leakage currents are observed in small transistor arrays to 10 Mrad(SiO/sub 2/). Standby currents of 256 K SRAMs are less than the 1.5 mA specification over the total dose range of 1 Mrad(SiO/sub 2/). The results suggest high density SRAMs and ASIC fabricated in this technology will perform well in harsh radiation environment.

Application of a model for treatment of time dependent effects on irradiation of microelectronic devices

A simple model for interpreting and extrapolating time-dependent effects in the irradiation of microelectronic devices is tested by fitting its predictions to published and previously unpublished experimental data. The goal is to evaluate the applicability of such a model to hardness assurance testing in cases where defect growth and annealing processes (time-dependent effects) are significant. Data are presented indicating hole annealing times varying by more than six orders of magnitude. The implications of the large variation in hole annealing times for hardness assurance testing are explored. >

Radiation response of fully-depleted MOS transistors fabricated in SIMOX

The total dose radiation response of radiation-resistant fully-depleted submicron n-MOS and p-MOS transistors fabricated in SIMOX is presented. The total ionizing dose radiation induced threshold voltage shifts under three different irradiation bias conditions, including the worst case (pass-gate) bias for n-MOS transistors are discussed. Total dose hard fully-depleted p-MOS transistors are experimentally demonstrated. The larger threshold voltage shifts of fully-depleted n-MOS transistors as compared to partially-depleted n-MOS transistors in an ionizing radiation environment are explained by a model coupling the radiation induced buried oxide charge to the top transistor. >

Reduction of radiation induced back channel threshold voltage shifts in partially depleted SIMOX CMOS devices by using ADVANTOX/sup TM/ substrates

Excessive total dose radiation induced back channel threshold voltage shifts often observed in fully depleted and partially depleted NMOS transistors fabricated in full dose SIMOX wafers can be greatly reduced by use of new low dose ADVANTOX/sup TM/ substrates.

Time dependence power laws of hot carrier degradation in SOI MOSFETS

The opposite channel based charge injection phenomenon in SOI MOSFETs provides a powerful tool, as it makes it possible for the first time to inject only holes or only electrons in regular, working MOSFETs. In this paper opposite channel based hot carrier injection has been combined with charge pumping measurements and the effects of pure hot electron/hole injection were investigated. n channel devices were used for the pure hole injection experiments, and p channel ones for the electron injection. The results demonstrate that both pure hole and pure electron injection give rise to interface state generation obeying a time power law. Based on these and other results, a conclusion is drawn that the purity of the injection pulse is responsible for the time power law, regardless of whether holes or electrons are injected. In contrast, when bipolar injection (mixture of holes and electrons) was applied, our results showed a familiar pattern.

A comparison of methods for simulating low dose-rate gamma ray testing of MOS devices

A radiation testing procedure is presented and experimentally verified in which a series of high-dose-rate irradiations, with 100 degrees C annealing under bias between irradiations, is used to simulate a continuous low-dose-rate irradiation. This approach can reduce low-dose-rate testing time by as much as a factor of 100 with respect to actual low-dose-rate irradiations. The procedure also provides detailed information on the behavior of CMOS parts at low dose-rates which are of interest to many satellite systems. >

Total dose performance at 77 K of a radiation hard 0.35 /spl mu/m CMOS SOI technology

This paper is the first demonstration that a 0.35 /spl mu/m CMOS technology designed to be radiation hard at room temperature is total ionizing dose radiation hard at 77 K to 1 Mrd (SiO/sub 2/). We compare radiation results from 0.35 /spl mu/m n-FETs irradiated with /sup 60/Co gamma rays at both 77 K and 300 K. We have demonstrated that interface traps play no appreciable role in the radiation performance of this technology at cryogenic temperatures.

Dose-rate-independent total dose failure in 54F10 bipolar logic circuits

The /sup 60/Co gamma ray total dose performance of unhardened bipolar 54F10 TTL (transistor transistor logic) integrated circuits was measured over dose rates from 0.0088 rad(SiO/sub 2/)/s to 28 rad(SiO/sub 2/)/s. Contrary to what others have reported on the 54F logic family, failure was independent of dose rate. This result implies that these parts are undesirable for use in a space environment. One manufacturers part failed due to excessive input high current at total doses from 20 to 30 krad(SiO/sub 2/) and the other failed at total doses from 7 to 9.5 krad(SiO/sub 2/). Thus, when considering a family of bipolar devices for application at space dose rates, each member of the family must be examined. It is pointed out that extrapolating total dose radiation measurements made at laboratory dose rates to sweeping conclusions about the performance of an unhardened process or device family at space dose rates can be misleading. >

Radiation response of ADVANTOX/sup TM/-190 SOI material

Summary form only given. In this paper, we describe the material properties and radiation properties of ADVANTOX/sup TM/-190 SOI material. This is a new ADVANTOX/sup TM/ with a thicker BOX at 190 nm. The ADVANTOX/sup TM/-190 SOI material has similar physical properties to ADVANTOX/sup TM/-120, such as low HF defect density and low dislocation density. Partially depleted SOI CMOS devices were fabricated to evaluate the radiation and speed performance of this new SOI material.