Robert C. Baumann

Radiation-induced soft errors in advanced semiconductor technologies

The once-ephemeral radiation-induced soft error has become a key threat to advanced commercial electronic components and systems. Left unchallenged, soft errors have the potential for inducing the highest failure rate of all other reliability mechanisms combined. This article briefly reviews the types of failure modes for soft errors, the three dominant radiation mechanisms responsible for creating soft errors in terrestrial applications, and how these soft errors are generated by the collection of radiation-induced charge. The soft error sensitivity as a function of technology scaling for various memory and logic components is then presented with a consideration of which applications are most likely to require soft error mitigation.

Soft errors in advanced semiconductor devices-part I: the three radiation sources

In this review paper, we summarize the key distinguishing characteristics and sources of the three primary radiation mechanisms responsible for inducing soft errors in semiconductor devices and discuss methods useful for reducing the impact of the effects in final packaged parts.

The impact of technology scaling on soft error rate performance and limits to the efficacy of error correction

The soft error rate (SER) of advanced CMOS devices is higher than all other reliability mechanisms combined. Memories can be protected with error correction circuitry but SER in logic may limit future product reliability. Memory and logic scaling trends are discussed along with a method for determining logic SER.

Impact of Low-Energy Proton Induced Upsets on Test Methods and Rate Predictions

Direct ionization from low energy protons is shown to cause upsets in a 65-nm bulk CMOS SRAM, consistent with results reported for other deep submicron technologies. The experimental data are used to calibrate a Monte Carlo rate prediction model, which is used to evaluate the importance of this upset mechanism in typical space environments. For the ISS orbit and a geosynchronous (worst day) orbit, direct ionization from protons is a major contributor to the total error rate, but for a geosynchronous (solar min) orbit, the proton flux is too low to cause a significant number of events. The implications of these results for hardness assurance are discussed.

Boron compounds as a dominant source of alpha particles in semiconductor devices

The interaction of cosmic ray neutrons and boron is demonstrated as the dominant source of alpha particles and other radiations in electronic devices utilizing borophosphosilicate glass (BPSG). A simple process modification is proposed to significantly reduce this intense source of ionizing radiation without compromising the reflow and passivation properties of BPSG.

Deposition and analysis of lithium niobate and other lithium niobium oxides by rf magnetron sputtering

The deposition of thin films of lithium niobate (LiNbO3) on silicon with rf magnetron sputtering has been investigated. A matrix of experiments was designed to determine the effect of several parameters on the resulting film quality. Under optimized conditions, oriented polycrystalline films of LiNbO3 are produced that exhibit a columnar grain structure with the polar axis normal to the substrate surface. Deviations from sputtering parameters optimized for producing LiNbO3, have been shown to produce films of varying proportions of either LiNb3O8 or Li3NbO4 with LiNbO3. The stoichiometry, microstructure, and electrical properties of selected films have been investigated with Rutherford backscattering, diffractometry, transmission electron microscopy, and a variety of electrical measurement techniques.

Muon-Induced Single Event Upsets in Deep-Submicron Technology

Experimental data are presented that show low-energy muons are able to cause single event upsets in 65 nm, 45 nm, and 40 nm CMOS SRAMs. Energy deposition measurements using a surface barrier detector are presented to characterize the kinetic energy spectra produced by the M20B surface muon beam at TRIUMF. A Geant4 application is used to simulate the beam and estimate the energy spectra incident on the memories. Results indicate that the sensitivity to this mechanism will increase for scaled technologies.

Neutron-induced 10B fission as a major source of soft errors in high density SRAMs

Abstract The impact of cosmic neutron induced 10 B fission in production submicron SRAM devices is reported for the first time. Using a cold neutron beam to accelerate soft error rate events, we unambiguously demonstrate that neutron induced 10 B fission can be a significant source of soft errors in deep-submicron SRAMs fabricated with borophosphosilicate glass.

Device-Orientation Effects on Multiple-Bit Upset in 65 nm SRAMs

The effects of device orientation on heavy ion-induced multiple-bit upset (MBU) in 65 nm SRAMs are examined. The MBU response is shown to depend on the orientation of the device during irradiation. The response depends on the direction of the incident ion to the n- and p-wells of the SRAM. The MBU response is simulated using Monte Carlo methods for a space environment. The probability is calculated for event size. Single-bit upsets in the space environment account for 90% of all events with exponentially decreasing probabilities of larger MBU events.

Boron as a primary source of radiation in high density DRAMs

The interaction of cosmic ray thermal neutrons and boron is demonstrated as the primary source of radiation in devices containing borophosphosilicate glass (BPSG). Simulations indicated that this source of radiation generates enough charge to induce soft errors in memory devices. The results of a study of DRAM devices also demonstrated that this radiation is capable of inducing soft errors. A simple process change that significantly reduces this source of radiation is proposed.