Download Pejcinovic Research 1.

High Frequency Design & Measurement
Dr. Branimir Pejcinovic, Dr. Melissa Holtzman and Betsy Natter
Microelectronics, Nanoelectronics and Electromagnetics
The limits of submicron CMOS are expected to be reached in the next few years.
Consequently, semiconductor research groups around the world are beginning to develop
computational devices at the molecular scale.
The focus areas of our program include nanodevices, packaging, design tools, circuits and
architecture.
Some noteworthy graduate student research includes:
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Investigating exotic semiconductor materials (InSb) and their application to
THz frequency range transistors. Different technologies (bulk InSB, InSB
on insulator, etc.) are examined and modeled.
Modeling of high frequency InSb MISFET devices using a full band Monte
Carlo simulator. The research is focused on the scalability of the device and
the effects of geometry changes on device performance.
Nonlinear modeling of GaAs MESFETs, with comparisons between
measured and simulated DC, C-V, and IMD responses.
Evaluating how accurately various BJT models predict IMD behavior in
HBTs at microwave frequencies. On-wafer measurements of SiGe and
GaAs HBTs are compared to simulated results.
Measuring and comparing the DC and RF characteristics of bulk Si,
strained-Si, SOI, and strained-SOI MOSFETs. Special emphasis is placed
on self-heating and other dispersion effects.
Characterizing the I-V properties of next generation avalanche photodiodes.
Dr. Holtzman’s background is in
semiconductor materials and devices, with
experience in III-V and II-VI compounds,
electronic sensors and radiation effects. She
has also worked in high-frequency electronics,
designing and building a prototype high-speed
frequency-hopping phase-locked loop
frequency synthesizer for military telemetry
applications.
Characterization and Comparison of SOI
and Strained-SOI N-MOSFETs
P. Wong, B. Pejcinovic, J. J. Lee, S. Hsu
Abstract — The operating performance of SOI and
strained-SOI N-MOSFETs are compared. In
particular, these properties are examined in detail:
1) electron mobility and DC characteristics, 2) high
frequency behavior, 3) dispersion and self-heating
effects, and 4) buried oxide interface trap density.
We show that SSOI technology can improve ft and
fmax conservatively by up to 50% without excessive
dispersion/self-heating. Measurements indicate the
SSOI wafer bonding process can produce an
acceptable buried oxide interface trap density.
Avalanche Photodiode
Test and
Characterization
APD 7-12 A2824A Gain
9
M. Compton
7
Multiplication Factor
6
5
Device 104
4
Device 113
Device 119
3
2
1
0
0
5
10
15
Bias Voltage
20
25
30
Abstract — In conjunction
with Voxtel Inc. and nLight
Photonics our laboratory has
characterized avalanche
photodiodes. The dark
current and the
photomultiplication, or gain,
of the devices are the primary
points of interest. The current
vs. voltage and gain of a
recent batch of devices, APD
7-12, are shown here.
Log I-V Curves for APD7-12 A2824A
1.00E-04
0
5
10
15
20
25
1.00E-05
1.00E-06
1.00E-07
Current
8
101 dark
101 1070nm LED
113 dark
113 1070nm LED
1.00E-08
119 dark
119 1070nm LED
1.00E-09
1.00E-10
1.00E-11
1.00E-12
Bias Voltage