Design of rad-hard SRAM cells: A comparative study

Abstract

Abstract-This paper presents the design of three static RAM cells, designed to be radiation hard. The memory cells are designed with three different approaches and layout styles. Three memory arrays, each of them made with a different cell, were designed and simulated to optimize the transistor sizes. The layout of the cells has been drawn, and parasitic elements were extracted to analyze their impact on circuit performance. Simulation results demonstrate that the three cells are functional in all worst case corners. The sensitivity of each cell to single events has been estimated using a fault injection technique. A silicon prototype employing the first cell has been fabricated and characterized.

CMOS IC radiation hardening by design

“…Compared to conventional layout design, ELTs and guard rings require a larger silicon area. Therefore, a higher level of radiati There are no sources in the current document.n tolerance can be achieved only at the expense of a larger area [15].…”

“…Another example is the "scrambling" in a memory array: the physical location of bits do not correspond to the logical bit position, to avoid logical Multiple Bit Upset (MBU) due to SEE. A further improvement can be obtained by storing each bit of a byte into a different memory array, and by providing each memory array with separate bit-line and word-line decoders, to avoid MBUs due to address upset [15].…”

A multi-megarad, radiation hardened by design 512 kbit SRAM in CMOS technology

“…With this approach, the area of a single SRAM cell is 16.58 µm 2 . Other layout designs have been explored, that provide different trade-offs between area and radiation hardness [5]. This design employs the cell with the best radiation hardness performance.…”

Estudo do tipo octo em ambientes de radiações ionizantes de raios-x

“…Além da preocupação em aumentar o desempenho elétrico dos MOSFETs, certas aplicações como as espaciais, nucleares e médicas requerem que eles sejam mais tolerantes às radiações ionizantes (Makowski, 2006). Existem diferentes formas para aumentar a tolerância às radiações ionizantes como, por exemplo, as técnicas de resistência à radiação por processo (radiation hardening by process RHBP) (Benigni, Liberali, Stabile, & Calligaro, 2010) e por projeto (radiation hardening by design RHBD) (Camplani, Shojaii, Shrimali, Stabile, & Liberali, 2014), onde as estruturas, os materiais e os leiautes dos MOSFETs, são alterados para atingir esses objetivos.…”