High resolution front-side visualization of charge stored in EEPROM with scanning nonlinear dielectric microscopy (SNDM)

X M Zeng; Q Liu; J Y Tay; K Y Chew; J Cheah; C L Gan

doi:10.1088/1361-6528/ac1ebd

High resolution front-side visualization of charge stored in EEPROM with scanning nonlinear dielectric microscopy (SNDM)

Nanotechnology. 2021 Sep 7;32(48). doi: 10.1088/1361-6528/ac1ebd.

Authors

X M Zeng¹, Q Liu¹, J Y Tay¹, K Y Chew¹, J Cheah¹, C L Gan^{1

2}

Affiliations

¹ Temasek Laboratories@NTU, Nanyang Technological University, 50 Nanyang Drive, 637553, Singapore.
² School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Drive, 639798, Singapore.

PMID: 34407521
DOI: 10.1088/1361-6528/ac1ebd

Abstract

By exposing floating gates of EEPROM memory cells with frontside sample preparation, scanning nonlinear dielectric microscopy (SNDM) succeeded in reading back the data stored in the memory cells with a 250 nm node size. At an optimized voltage bias of AC = 3 V and DC = 1 V, a clear signal contrast between programmed and erased cells is obtained. The high resolution SNDM signal reveals the details of bowling-pin shape structure of memory cells, providing high confidence in data assignment during forensic applications. Such high resolution also makes SNDM a promising technique for newer generation devices with smaller node size.

Keywords: data retrieval; floating gate of EEPROM; frontside sample preparation; scanning nonlinear dielectric microscopy.