NANOMILLING OF A SUB-50 NM INDIUM ARSENIDE COMPOSITE CHANNEL HIGH ELECTRON MOBILITY TRANSISTOR

摘要

The sub-50 nm Indium Arsenide Composite Channel (IACC) High Electron Mobility Transistors (HEMTs) are fabricated on 100 mm Indium Phosphide (InP) substrates. This technology offers the best performance for low-noise and high-frequency, space and military applications. Typical failure mechanisms are observed in III-V HEMT technologies, including gate sinking, impact ionization and electromigration. Experiments were conducted to understand failure mechanisms of the IACC HEMTs by life testing devices at accelerated temperatures and biases; their electrical characteristics were measured at each stress interval. Since many of the known III-V semiconductor failure mechanisms physically degrade or damage HEMTs, cross-sections are important to prepare to detect these mechanisms. In this presentation, advanced microscopy techniques with sub-nanometer resolutions, will examine physical characteristics of the HEMT at the atomic scale. The microscopy techniques will include a Focused Ion Beam/Scanning Electron Microscope (FIB/SEM) to prepare cross-sections of the HEMT and a Scanning Transmission Electron Microscope (STEM) to examine the physical features. A Nanomill is used to supplement the FIB by further thinning the sample to see the atomic features and remove any amorphous layers left behind by the FIB. This presentation will show how the Nanomill helps to uncover the atomic-scale features of the HEMT.