Direct Measurements of Charge in Floating Gate Transistor Channels of Flash Memories Using Scanning Capacitance Microscopy

Nardi, Christophe De; Desplats, Romain; Perdu, Philippe; Guérin, Christophe; Gauffier, Jean Luc; Amundsen, Thomas B.

doi:10.31399/asm.cp.istfa2006p0086

Cited by 8 publications

(4 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Some studies have used scanning capacitance microscopy to read the contents of memory cells. De Nardi et al [7] have successfully used scanning capacitance microscopy to read memory devices that were extensively prepared for the scanning capacitance microscopy technique. They were able to distinguish between cells containing bit values of 1 and 0, and to recreate word-length data from scanning capacitance microscopy images.…”

Section: Prior Artmentioning

confidence: 99%

“…The scanning capacitance microscopy study by De Nardi et al [7] and the electrical force microscopy study by Konopinski [14] both involved the extraction of the die from the memory device and thinning it from the backside, reducing the chip thickness until the underside of the active circuits was almost exposed. This is not a trivial procedure, but is necessary, especially in the case of scanning capacitance microscopy, which relies on band-bending induced by the electric field from the tip to create a signal.…”

Section: Prior Artmentioning

confidence: 99%

See 1 more Smart Citation

Digital Forensic Atomic Force Microscopy of Semiconductor Memory Arrays

Gray

Axelsson

2019

Advances in Digital Forensics XV

View full text Add to dashboard Cite

Atomic force microscopy is an analytical technique that provides very high spatial resolution with independent measurements of surface topography and electrical properties. This chapter assesses the potential for atomic force microscopy to read data stored as local charges in the cells of memory chips, with an emphasis on simple sample preparation ("delidding") and imaging of the topsides of chip structures, thereby avoiding complex and destructive techniques such as backside etching and polishing. Atomic force microscopy measurements of a vintage EPROM chip demonstrate that imaging is possible even when sample cleanliness, stability and topographical roughness are decidedly suboptimal. As feature sizes slip below the resolution limits of optical microscopy, atomic force microscopy offers a promising route for functional characterization of semiconductor memory structures in RAM chips, microprocessors and cryptographic hardware.

show abstract

Section: Prior Artmentioning

confidence: 99%

Section: Prior Artmentioning

confidence: 99%

Digital Forensic Atomic Force Microscopy of Semiconductor Memory Arrays

Gray

Axelsson

2019

Advances in Digital Forensics XV

View full text Add to dashboard Cite

show abstract

“…Scanning Kelvin Probe Microscopy (SKPM), Electrical Force Microscopy (EFM), and Scanning Capacitance Microscopy (SCM) to probe and measure the charges in the FG of Flash and EEPROM directly [10,[12][13][14][15][16][17][18]. The number of charges in the FG can vary from 10 5 in the older technology nodes to less than 10 3 in the advanced chips.…”

Section: Different Research Teams Have Done Studies Using Electrical ...mentioning

confidence: 99%

“…12 (a) shows an in-plane magnetized sample while Figure3-12 (b) shows an out-of-plane magnetized sample. [11] According to literature review, MR256A08B sample, which is a toggle MRAM, has inplane magnetization.…”

mentioning

confidence: 99%

Investigation on the security of stored data in emerging non-volatile memory devices using AFM- based techniques

Tay¹

View full text Add to dashboard Cite

Nowadays, non-volatile memory (NVM) devices are extensively used for information storage in artificial intelligence, communication, transportation, mobile and many other applications. With their intended use in these applications, it is important to evaluate the security of stored data in these devices against extraction or modification. Hardware security analysis includes physical attacks and software attacks. Prior studies have been conducted on NVMs such as Flash and EEPROM devices using Atomic Force Microscopy (AFM) based techniques. AFM is a versatile tool that can measure different material properties along with topography and morphology information. This makes it suitable for the investigation on the emerging NVMs such as magnetic random-access memory (MRAM), ferroelectric random-access memory (FeRAM), phase-change memory (PCM), and resistive random-access memory (RRAM) in the market.In this study, RRAM and MRAM devices that are available in the market will first be analyzed through the use of failure analysis techniques such as chemical deprocessing, Xray imaging and scanning electron microscopy (SEM) with focused ion beam (FIB) to understand its device architecture. Next, deprocessing steps such as chemical etching and reactive ion etching will be developed to access the data storage layer of the RRAM/MRAM where the devices store their data depending on the resistance state, which corresponds to the binary bit of '1' or '0'. Then, the AFM technique such as conductive probe AFM (CP-AFM), using a constant dc bias, will be used to scan across the sample's surface and directly probe on the data storage layer to measure the current and thus its resistance. The collected results from the current scans will be validated with the input data in order to assess the accuracy of the technique. Precaution measures adopted to prevent the loss of data during the sample preparation process will also be discussed. The first ever successful readout of data in RRAM samples using CP-AFM has been achieved and block level data organization of the memory is also presented in this study, thus demonstrating the vulnerability of RRAM devices to security attacks, and potentially MRAM technology as well.

show abstract