Dongwoo Lee

In this paper we address the growing issue of gate oxide leakage current (I/sub gate/) at the circuit level. Specifically, we develop a fast approach to analyze the total leakage power of a large circuit block, considering both I/sub gate/ and subthreshold leakage (I/sub sub/). The interaction between I/sub sub/ and I/sub gate/ complicates analysis in arbitrary CMOS topologies and we propose simple and accurate heuristics based on lookup tables to quickly estimate the state-dependent total leaka

In this paper we address the growing issue of gate oxide leakage current (I gate) at the circuit level. Specifically, we develop a fast approach to analyze the total leakage power of a large circuit block, considering both I gate and subthreshold leakage (I sub). The interaction between I sub and I gate complicates analysis in arbitrary CMOS topologies and we propose simple and accurate heuristics based on table look-ups to quickly estimate the state-dependent total leakage current within 1 % of

We present the design and fabrication of centimeter scale robots, which use inchworm-like motion and bidirectional claws. Two prototypes for different locomotion goals were built utilizing these two characteristics: Type I is designed particularly for horizontal surfaces utilizing two linear actuators and compliant claws. This robot is capable of steering and straight motion by utilizing directionally anisotropic friction. Type II is a variant of Type I that is designed for locomotion on ferroma

Presilicon testing and verification is a crucial step in qualifying the RTL for the subsequent implementation phases. This article presents a novel simulation-based fault injection methodology that is applied at the system description level, as opposed to the lower, flattened RT level, in order to reduce simulation time.

We demonstrate a route to synthesize ultra-high-temperature ceramic coatings of ZrB2 at temperatures below 1300 K using Zr/B reactive multilayers. Highly textured crystalline ZrB2 is formed at modest temperatures because of the absence of any oxide at the interface between Zr and B and the very short diffusion distance that is inherent to the multilayer geometry. The kinetics of the ZrB2 formation reaction is analyzed using high-temperature scanning nanocalorimetry, and the microstructural evolu

We propose a new method that uses a combined approach of sleep-state assignment and threshold voltage (Vt) assignment in a dual-Vt process. While each of these methods has previously been used individually, their combined effect has not been leveraged to date. By combining Vt and sleep-state assignment, leakage current can be dramatically reduced since the circuit is in a known state in standby-mode and only transistors that are off need to be considered for high-Vt assignment. A significant imp

In this paper we develop a fast approach to analyze the total leakage power of a large circuit block, considering both gate leakage, I/sub gate/, and subthreshold leakage, I/sub sub/. The interaction between I/sub sub/ and I/sub gate/ complicates analysis in arbitrary CMOS topologies. We propose simple and accurate heuristics to quickly estimate the state-dependent total leakage current considering the interaction between I/sub sub/ and I/sub gate/. We apply this method to ISCAS benchmark circui

The reaction of Zr/B multilayers with a 50 nm modulation period has been studied using scanning AC nanocalorimetry at a heating rate of approximately 103 K/s. We describe a data reduction algorithm to determine the rate of heat released from the multilayer. Two different exothermic peaks are identified in the nanocalorimetry signal: a shallow peak at low temperature (200–650 °C) and a sharp peak at elevated temperature (650–800 °C). TEM observation shows that the first peak corresponds to hetero

The thermodynamics and kinetics of the solid-state alloying of Zr-B, underlying a variety of synthesis processes of the ultrahigh-temperature ceramic ZrB2, are widely unknown. We investigate the energetics, diffusion kinetics, and structural evolution of this system using first-principles computational methods. We identify the diffusion pathways in the interpenetrating network of interstitial sites for a single B atom and demonstrate a dominant rate-controlling step from the octahedral to the cr