Hardness variability in commercial technologies

Abstract

budgets, there has been a drastic decrease in the dollar value of the radiation-hardened integrated circuit The radiation hardness of commercial Floating (IC) market, and a concomitant reduction in the Gate 256K E2PROMs from a single diffusion lot number of viable suppliers of radiation-hardened was observed to vary between 5 to 25 krad(Si) when ICs. This trend is expected to continue for the foreirradiated at a low dose rate of 64 mrad(Si)/s. Addi-seeable future. In addition, the capability of radiational variations in E'PROM hardness were found tion-hardened technologies has traditionally lagged to depend on bias condition and failure mode (Le., one to two generations behind commercial technolinability to read or write the memory), as well as the foundry at which the part was manufactured. This variability is related to system requirements, and it is shown that hardness level and variability affect the allowable mode of operation for E2PROMs in space applications. The radiation hardness of commercial 1-Mbit CMOS SRAMs from Micron, Hitachi, and Sony irradiated at 147 rad(Si)/s was approximately 12, 13, and 19 krad(Si), respectively. These failure levels appear to be related to increases in leakage current during irradiation. Hardness of SKAMs from each manufacturer varied by less than 20%, but differences between manufacturers are ogies, leading to reduced system performance. This has prompted a renewed interest in the use of commercial technology -with its enhanced performance and yield, and reduced cost -in military and space systems. But unlike the vendors of hardened technologies, the commercial manufacturer has no interest in identifying and controlling the technology parameters that affect radiation hardness. As such, we expect lower hardness levels for commercial technologies and, perhaps even more importantly, greater variability of commercial technologies in a radiation environment.significant. The Qualified Manufacturer's List approach to radiation hardness assurance is suggested as a way to reduce variability and to improve the hardness level of commercial technologies.In Figure 1 we show the total-dose requirements for pieceparts used on several space-based vehicles, and payloads located on space-based vehicles, as a function of orbit altitude. The vehicle and payload

Recent progress in front end ASICs for high-energy physics

“…Previously, tests on commercial parts from different manufacturers had shown large variations in hardness, even across wafers [13,17,18]. What was pointed out in a study led by the CERN Microelectronics Group [19] was that 0.25 mm CMOS transistors showed especially good behaviour compared to coarser technologies in leakage current, threshold voltage shifts and transconductance behaviour at Mrad levels and the results suggested that higher doses could be tolerated.…”

Radiation Effects In Space

“…Most standard commercial devices fail somewhere in the range of 3-30 krad (SiO 2 ) [6]. However, higher dose rad-hard electronics can be fabricated depending upon the specific needs at higher cost due to their very limited market.…”

“…Total-dose hardness requirements in krad (Si) for several satellite systems as a function of orbit altitude (After Ref 6). …”

Radiation effects in the space telecommunications environment

“…Most standard commercial devices fail somewhere in the range of 3-30 krad(SiO2) [5], [43], [44]. However, there are recent reports of parts fabricated in at least one commercial foundry with hardness greater than 100 krad(SiO2) [45], so one must take care not to over-generalize conclusions in this area.…”

“…2 shows total dose levels for some systems with which Sandia National Laboratories has been involved in the past [43]. Clearly, low-Earth orbits are generally more benign than higher orbits.…”