High Frequency Design

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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
• 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. Holtzmans 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 M.
Compton  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.