Single Event Effect Essay

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Reliability is one of the most important factors in circuit design. For modern CMOS technology, the circuit reliability is influenced by the shrinking of technology, the reduced supply voltage, higher frequency, and higher circuit density. These factors affects the circuit's probability of soft errors (also called single event upset). In addition, the process variation introduced in the fabrication process is also a big challenge for circuit designers because it makes the same circuit show different characteristics. Moreover, to reduce power consumption of the circuit, the method of reducing supply voltage to near threshold region is used, which is anticipated to have more effects on the reliability of the circuit. So the relationship between …show more content…

Single event effects can induce destructive and nondestructive damage to the circuit. In this thesis, only the nondestructive single event effect is taken into account.

The basic mechanism for the single event effect in microelectronics includes the charge deposition and the charge collection. In the charge deposition process, there are two ways to release charge in semiconductor devices: (1) direct ionization is caused by the incident particles, and (2) indirect ionization is caused by the nuclear reaction between the incident particle and the device. Usually the deposition mechanism for heavy ions like alpha particles is mainly direct ionization, and light particles like protons and neutrons can result in single event upset by indirect ionization \cite{1208578}.

For direct ionization, when a particle hits the silicon substrate, a track of electron-hole pairs (EHPs) is generated as the particle travels through the material and loses energy along its path. For indirect ionization, as the light particles enter the semiconductor device, nuclear reactions will occur: (1) elastic collision; (2) the emission of alpha or gamma particles and the recoil of a daughter nucleus; (3) spallation reactions. The products of these reactions can deposit energy along their path by direct ionization

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