High-resolution EBIC system for scanning transmission electron microscopy of advanced infrared semiconductor devices

Sivananthan Laboratories proposes to design an electron-beam induced current (EBIC) platform capable of performing high-resolution carrier lifetime, mobility and diffusion length measurements at point and extended defects in small-band gap semiconductor interfaces for infrared detectors. The proposed design includes a micro-electro-mechanical systems (MEMS)-based double-tilt heating stage and will allow for simultaneous atomic-resolution imaging in a scanning transmission electron microscopy (STEM) mode. Additional electronics will be integrated onto the e-chips to locally amplify and convert the generated current and display the EBIC signal. The PIs will also demonstrate that cross-sectional TEM samples for the newly-designed EBIC system can be prepared using conventional focused ion-beam lamellas, where the sample is connected to the current read-outs using e-beam-deposited Pt. To demonstrate the feasibility of the approach, STEM imaging, electron spectroscopy (i.e. EELS or XEDS) and initial EBIC analysis will be performed of dislocations in HgCdTe single-junction, short-wavelength infrared (SWIR) and mid-wavelength infrared (MWIR) devices. Sivananthan Laboratories has the mission to develop and commercialize new advances in materials science in support of the US government, US military, and the defense industry. It has extensive experience in the defect analysis of HgCdTe devices and collaborates with local TEM experts to perform the STEM measurements.