Mohammad Najmzadeh | University of California, Berkeley (original) (raw)

Uploads

Papers by Mohammad Najmzadeh

Applied Physics Express, 2016

2015 73rd Annual Device Research Conference (DRC), 2015

A top-down Si nanowire platform is developed to make dense array of gate-all-around (GAA) Si nano... more A top-down Si nanowire platform is developed to make dense array of gate-all-around (GAA) Si nanowire MOSFETs with scalable nanowire cross-section down to 4 nm on a SOI substrate. High level of local uniaxial stress (both tensile and compressive) can be integrated to this Si nanowire platform using e.g. metal gate strain and local oxidation to boost the carrier mobility. Nanowire pattern transfer to the wafer in the presence of hard mask, Si nanowire side-wall engineering by anisotropic dry Si etching (HBr/O2) to shrink further the cross-section, stress-limited oxidation and ALD high-k/metal gate stack are the key process steps. A high level of uniaxial tensile stress (up to 5.6 GPa) is estimated in the buckled GAA Si nanowires based on a Gaussian buckling profile assumption, using top and tilted-view nanowire SEM pictures. Indeed, a significant stress level modulation (~1.2 to 5.6 GPa) is reported by the Si nanowire width modulation (44 to 4 nm) at a constant nanowire length (2 μm)...

The precision of carrier mobility extraction in a JAM device strongly depends on the doping level... more The precision of carrier mobility extraction in a JAM device strongly depends on the doping level in the S/D extensions. The bias-dependency of several key MOSFET parameters (e.g. gate-channel capacitance, effective channel width and series resistance) together with the non-linear mobile charge accumulation in the channel due to the corners in the GAA Si nanowires, with cross-section down to 5 nm, and their impacts on the carrier mobility extraction are addressed in details for the first time.

The resonance frequency of a suspended fluid-conveying Si micro-tube bridge resonator depends on ... more The resonance frequency of a suspended fluid-conveying Si micro-tube bridge resonator depends on its mass, which is a function of the density of the fluid inside the suspended bridge Si micro-tube.

IEEE Transactions on Nanotechnology, 2015

Solid-State Electronics, 2010

Microelectronic Engineering, 2010

Microelectronic Engineering, 2009

Journal of Micromechanics and Microengineering, 2007

IEEE Transactions on Electron Devices, 2010

About the cover: Top-view SEM micrograph of a multi-gate dual Si nanowire MOSFET on bulk Si. The ... more About the cover: Top-view SEM micrograph of a multi-gate dual Si nanowire MOSFET on bulk Si. The in-plane nanowire buckling is a sign of uniaxial tensile stress in the channel. The arrow indicates the scan axis and direction of the laser spot in the micro-Raman measurement.

Abstract—In this paper, we report, for the first time, corner effect analysis in the gate-all-aro... more Abstract—In this paper, we report, for the first time, corner effect analysis in the gate-all-around equilateral triangular silicon nanowire (NW) junctionless (JL) nMOSFETs, from subthreshold to strong accumulation regime. Corners were found to accumulate and deplete more electrons than the flat sides or the channel center, when above (local accumulation) and below (local depletion) the flat-band voltage, respectively. On the contrary to the corner effect in the inversion mode (IM) devices, there is no major contribution of corners in the subthreshold current, and therefore, there is no subthreshold device behavior degradation (only one threshold voltage in the system). N-type channel doping levels of 1 × 10 19,5 × 10 18,and1 × 10 18 cm−3 were used for quasi-stationary device simulations of JL and AM MOSFETs, and corner effect was studied for 5, 10, and 15 nm wide equilateral triangular Si NW MOSFETs with a 2 nm SiO2 gate oxide thickness (VDS = 0V;T = 300 K). While the local quantum...

Keywords: Si nanowire ; Strain engineering ; Local oxidation ; Uniaxial tensile stress ; CMOS boo... more Keywords: Si nanowire ; Strain engineering ; Local oxidation ; Uniaxial tensile stress ; CMOS booster Reference NANOLAB-CONF-2008-017 Record created on 2009-07-15, modified on 2017-05-10

Keywords: Straight Si tube ; Fluid-conveying Si microtube ; Bridge resonator ; Fluid density sens... more Keywords: Straight Si tube ; Fluid-conveying Si microtube ; Bridge resonator ; Fluid density sensor ; Microfluidic Reference EPFL-CONF-175287 URL: http://www.cbmsociety.org/conferences/microtas2007/ Record created on 2012-03-01, modified on 2017-05-10

L. Lattanzio, L. De Michielis, M. Najmzadeh, A.M. Ionescu, Nano Tech (the world's largest ex... more L. Lattanzio, L. De Michielis, M. Najmzadeh, A.M. Ionescu, Nano Tech (the world's largest exhibition on nanotechnology), Tokyo, Japan, 2011 (poster; promoted by the Swiss Embassy in Japan at the Swiss Pavilion).