This paper provides a historical review of the literature on the effects of radiation-induced displacement damage in semiconductor materials and devices. Emphasis is placed on effects in technologically important bulk silicon and silicon devices. The primary goals are to provide a guide to displacement damage literature, to offer critical comments regarding that literature in an attempt to identify key findings, to describe how the understanding of displacement damage mechanisms and effects has evolved, and to note current trends. Selected tutorial elements are included as an aid to presenting the review information more clearly and to provide a frame of reference for the terminology used. The primary approach employed is to present information qualitatively while leaving quantitative details to the cited references. A bibliography of key displacement-damage information sources is also provided.

Review of displacement damage effects in silicon devices

A review of radiation-induced displacement damage effects in semiconductor devices is presented, with emphasis placed on silicon technology. The history of displacement damage studies is summarized, and damage production mechanisms are discussed. Properties of defect clusters and isolated defects are addressed. Displacement damage effects in materials and devices are considered, including effects produced in silicon particle detectors, visible imaging arrays, and solar cells. Additional topics examined include NIEL scaling, carrier concentration changes, random telegraph signals, radiation hardness assurance, and simulation methods for displacement damage. Areas needing further study are noted.

Displacement Damage Effects in Irradiated Semiconductor Devices

Photonic imagers are being increasingly used in space systems, where they are exposed to the space radiation environment. Unique properties of these devices require special considerations for radiation effects. This paper summarizes the evolution of radiation effects understanding in infrared detector technology, charge coupled devices, and active pixel sensors. The paper provides a discussion of key radiation effects developments and a view of the future of the technologies from a radiation effects perspective.

Radiation effects on photonic imagers-a historical perspective

The dark current increase due to proton-induced displacement damage is studied in a standard and a radiation-hardened CMOS active pixel sensor (APS). Several devices have been irradiated with protons of different energies and fluences. The influence of the proton energy and fluence on the mean dark current increase and the dark current nonuniformity is investigated. Dark current density histograms are obtained by the theory based on collision kinematics. They are determined by the number of elastic and inelastic collisions and the damage these interactions create in the pixel sensitive volume. It is shown that field enhanced emission has to be taken into account to predict accurately the distribution of the dark current density increase. We also compare the results with data found in literature for charge coupled devices (CCD) and charge injection devices (CID).

Enhanced dark current generation in proton-irradiated CMOS active pixel sensors

A framework is presented for understanding carrier generation and recombination mechanisms in irradiated silicon devices. Data obtained by many workers for irradiated bulk material and devices are analyzed and summarized, and key damage-factor dependences are identified. Measurements, simulations, and analyses support the conclusion that correlation of displacement damage effects with the rate of nonionizing energy loss (NIEL) for proton, neutron, pion, and heavy-ion bombardment is due to the dominant influence of defect subclusters. At low NIEL values ( 2times10-4 MeV-cm2/g), subclusters dominate. Enhanced carrier generation and recombination produced by those small disordered regions is considered. Modeling results are presented for behavior observed in the transition region between domination by isolated defects and by clusters. The model presented in this paper simultaneously accommodates defect cluster models and NIEL scaling phenomena in the same framework

A Framework for Understanding Displacement Damage Mechanisms in Irradiated Silicon Devices

A new damage factor formulation is presented for describing radiation-induced dark current in silicon devices. This damage factor, K/sub dark/, is the number of carriers thermally generated per unit volume per unit time in a depletion region per unit nonionizing dose deposited in that volume. K/sub dark/ appears to account successfully for the mean radiation-induced dark current for any silicon device in which thermal generation at bulk centers dominates. This dark-current damage factor applies for devices in all radiation environments except those that produce relatively isolated defects. Evidence is presented which strongly indicates that the defects responsible for dark current increases are not associated with impurities.

D.H. Lo

Papers

Universal damage factor for radiation-induced dark current in silicon devices

Optical pumping of deep traps in AlGaN/GaN-on-Si HEMTs using an on-chip Schottky-on-heterojunction light-emitting diode