A Floating Gate MOSFET Based Current Reference with Subtraction Technique

Abstract In this paper, the authors report their successful attempt to acquire the scanning nonlinear dielectric microscopy (SNDM) signals around the floating gate and channel structures of the 3D Flash memory device, utilizing the custom-built SNDM tool with a super-sharp diamond tip. The report includes details of the SNDM measurement and process involved in sample preparation. With the super-sharp diamond tips with radius of less than 5 nm to achieve the supreme spatial resolution, the authors successfully obtained the SNDM signals of floating gate in high contrast to the background in the selected areas. They deduced the minimum spatial resolution and seized a clear evidence that the diffusion length differences of the n-type impurity among the channels are less than 21 nm. Thus, they concluded that SNDM is one of the most powerful analytical techniques to evaluate the carrier distribution in the superfine three dimensionally structured memory devices.

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Investigations of Leakage Paths in Sub-0.35μm DRAM Products Using Advanced Focused Ion Beam Techniques

ISTFA 1998: Conference Proceedings from the 24th International Symposium for Testing and Failure Analysis ◽

10.31399/asm.cp.istfa1998p0289 ◽

1998 ◽

Author(s):

H. Lorenz ◽

C. Engel

Keyword(s):

Focused Ion Beam ◽

Cell Function ◽

Dielectric Breakdown ◽

Ion Beam ◽

Electrical Characterization ◽

Floating Gate ◽

Leakage Path ◽

Contrast Technique ◽

Voltage Contrast

Abstract Due to the continuously decreasing cell size of DRAMs and concomitantly diminishing thickness of some insulating layers new failure mechanisms appear which until now had no significance for the cell function. For example high resistance leakage paths between closely spaced conductors can lead to retention problems. These are hard to detect by electrical characterization in a memory tester because the involved currents are in the range of pA. To analyze these failures we exploit the very sensitive passive voltage contrast of the Focused Ion Beam Microscope (FIB). The voltage contrast can further be enhanced by in-situ FIB preparations to obtain detailed information about the failure mechanism. The first part of this paper describes a method to detect a leakage path between a borderless contact on n-diffusion and an adjacent floating gate by passive voltage contrast achieved after FIB circuit modification. In the second part we will demonstrate the localization of a DRAM trench dielectric breakdown. In this case the FIB passive voltage contrast technique is not limited to the localization of the failing trench. We can also obtain the depth of the leakage path by selective insitu etching with XeF2 stopped immediately after a voltage contrast change.

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Floating Gate Memory Based on Ferritin Nanodots with High-kGate Dielectrics

Japanese Journal of Applied Physics ◽

10.1143/jjap.48.04c153 ◽

2009 ◽

Vol 48 (4) ◽

pp. 04C153 ◽

Cited By ~ 8

Author(s):

Kosuke Ohara ◽

Yukiharu Uraoka ◽

Takashi Fuyuki ◽

Ichiro Yamashita ◽

Toshitake Yaegashi ◽

...

Keyword(s):

Floating Gate ◽

Floating Gate Memory

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Novel capacitance coupling coefficient measurement methodology for floating gate nonvolatile memory devices

IEEE Electron Device Letters ◽

10.1109/led.2005.851171 ◽

2005 ◽

Vol 26 (7) ◽

pp. 507-509 ◽

Cited By ~ 7

Author(s):

R. Duane ◽

M.F. Beug ◽

A. Mathewson

Keyword(s):

Coupling Coefficient ◽

Nonvolatile Memory ◽

Floating Gate ◽

Memory Devices ◽

Nonvolatile Memory Devices ◽

Measurement Methodology ◽

Coefficient Measurement ◽

Capacitance Coupling

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Simulation of proppant transport and fracture plugging in the framework of a radial hydraulic fracturing model

Russian Journal of Numerical Analysis and Mathematical Modelling ◽

10.1515/rnam-2020-0027 ◽

2020 ◽

Vol 35 (6) ◽

pp. 325-339

Author(s):

Vasily N. Lapin ◽

Denis V. Esipov

Keyword(s):

Numerical Model ◽

Hydraulic Fracturing ◽

Oil And Gas ◽

Oil And Gas Industry ◽

Injection Rate ◽

Fluid Injection ◽

Subtraction Technique ◽

Gas Industry ◽

Proppant Transport ◽

Hydraulic Fracture Propagation

AbstractHydraulic fracturing technology is widely used in the oil and gas industry. A part of the technology consists in injecting a mixture of proppant and fluid into the fracture. Proppant significantly increases the viscosity of the injected mixture and can cause plugging of the fracture. In this paper we propose a numerical model of hydraulic fracture propagation within the framework of the radial geometry taking into account the proppant transport and possible plugging. The finite difference method and the singularity subtraction technique near the fracture tip are used in the numerical model. Based on the simulation results it was found that depending on the parameters of the rock, fluid, and fluid injection rate, the plugging can be caused by two reasons. A parameter was introduced to separate these two cases. If this parameter is large enough, then the plugging occurs due to reaching the maximum possible concentration of proppant far from the fracture tip. If its value is small, then the plugging is caused by the proppant reaching a narrow part of the fracture near its tip. The numerical experiments give an estimate of the radius of the filled with proppant part of the fracture for various injection rates and leakages into the rock.

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