Sandia Labs FY21 LDRD Annual Report

FY21 ANNUAL REPORT

Expanding performance limits using ultrafast electron microscopy. Thermal imaging is used extensively in national security missions, so it is essential to identify the performance- limiting mechanisms in mid- to far infrared sensors. This LDRD probed photogenerated free carrier dynamics in model detector materials using scanning ultrafast electron microscopy (SUEM) to identify the mechanisms. SUEM combines ultrafast electron pulses with optical excitations in a pump-probe configuration to measure charge dynamics in semiconductors with high spatial and temporal

resolution and without the need for microfabrication. A SUEM tool was constructed (one of only two in the world) and used to examine several semiconductor systems relevant to detectors. A new contrast mechanism potentially useful for next-generation chip fabrication was discovered, which will enable ultrafast probing of defects and contaminants at deeply buried oxide/semiconductor interfaces. (PI: A. Alec Talin) Moving toward modernized strategic radiation-hardened microelectronics technology. Enabling Sandia to field a sub-100-nm strategically radiation hardened (SRH) CMOS technology would vastly improve the effectiveness of critical national security mission systems, including those relevant to nuclear deterrence and non-proliferation. With that goal in mind, the research team created a novel metal oxide semiconductor (MOS) capacitor architecture, demonstrated a functional n-MOS field-effect transistor with a metal gate process, developed techniques to probe electrically active interface traps, and designed a simulation methodology for resistor-capacitor hardening of devices and circuits. By identifying scientific solutions for engineering problems, researchers successfully highlighted a new path for SRH technology that can improve speed and computing power without sacrificing Sandia’s integrated circuits’ world-class performance in harsh environments. (PI: Mike King) The scanning ultrafast microscopy tool built at Sandia and its basic operation mechanism.

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LABORATORY DIRECTED RESEARCH & DEVELOPMENT