Product Assurance Technology for Procuring Reliable , Radiation - Hard , Custom LSI / VLSI Electronics Report for Period

In this effort, advanced measurement methods that use microelectronic test chips are described. These chips are intended to be used in acquiring the data needed to qualify Application Specific Integrated Circuits (ASICs) for space use. This work represents the collaborative effort of integrated-circuit (IC) parts specialists, device physicists, test-chip engineers, and fault-tolerant-circuit designers. Their efforts were focused on developing the technology for obtaining custom ICs from CMOS/bulk silicon foundries. In pursuit of this goal a series of test chips has been developed: a Parametric Test Strip, a Fault Chip, a set of Reliability Chips, and the CRRES (Combined Release and Radiation Effects Satellite) Chip, a test circuit for monitoring space radiation effects. The technical accomplishments of this effort include: 1. Development of a Fault Chip that contains a set of test structures used to evaluate the density of various process-induced defects. In addition, procedures were developed to determine which defects are most likely to cause failures in concurrently fabricated circuits. In the reporting period, seven versions of the fault chip have been prepared. 2. Development of new test structures and testing techniques for measuring gate-oxide capacitance, gate-overlap capacitance, and propagation delay. . Development of a set of Reliability Chips that are used to evaluate failure mechanisms in CMOS/Bulk: interconnect and contact electromigration and time-dependent dielectric breakdown. 4. Development of MOSFET parameter extraction procedures for evaluating subthreshold characteristics. , Evaluation of Test Chips and Test Strips on the second CRRES wafer run. This data was used to analyze wafer-level test structure requirements demonstrating that sufficient data to characterize the wafer run could be acquired from a limited number of drop-in sites (for example, nine). . Two dedicated fabrication runs for the CRRES Chip flight parts. Flight parts from these runs were shipped to the CRRES program in March, 1986. Radiation tests (Total Integrated Dose and Single Event Upset) were performed on these parts. 7. Publication of two papers: one on the Split-Cross Bridge Resistor and another on Asymmetrical SRAM Cells for Single-Event Upset Analysis.