Laboratories

Baskin Engineering 262: 600 sq feet class-10K cleanroom for processing of semiconductor devices (4 class 100 laminar flow exhaust fume hoods)
Baskin Engineering 299: 400 sq feet characterization laboratory with 4’x8’ and 4’x10’ optical tables
Baskin Engineering 148: 400 sq feet ultra optical laboratory with 4’x10’ optical tables

Major Equipment

Riber 2300 Solid Source Molecular Beam Epitaxy machine
JobinYvon/Horiba Raman and Luminescence Spectroscopy System
Coherent Mira 900 Femto/Picosecond Laser
UCSC Camera high resolution thermal imaging system(sub-micro, 0.25K resolution)
Centre Suisse d'Electronique optical coherence tomography camera (OCT)
Janis high temperature cryostat system CCS-450-H-204 (4~800K)
Digital Instruments Dimension 3100 Atomic Force Microscope with scanning capacitance and NSOM capability
3.6 Gb/s Agilent Bit Error Rate Analyzer
Nicolet Nexus 870 Fourier Transfer Infrared Spectrometer (12,000-600 cm-1)
Optical Spectrum Analyzer (500-1800nm)
Cryostat for microscopy and for optical transmission measurements (4-450K)
RF probe station with Cascade 40GHz micropositioners
20GHz sampling scope with TDR, 2x 500MHz Digital Scopes
Synthesized Swept-Signal Generator, 0.01 - 50 GHz
Portable Spectrum Analyzer, 9 kHz to 50 GHz
Synthesized CW Generator, 10 MHz to 20 GHz
Vector Signal Generator 1-250MHz and Modulation Analyzer
Noise and Interface Test Set
Lock-in Amplifier (DSP 100KHz and 200MHz, Analog 120KHz)
FFT Spectrum Analyzer (120KHz)
Pulse generators (3ns rise time, 20V pulse module)
Turbo pumping station
West Bond Wire Bonding Machine
FiberAlign high precision computer-controlled XYZ translation stage (6"x2"x1" travel, 25nm resolution)
High-performance multimeters, nanovoltmeters, sub-femtoamp source meter, and 30MHz function generators
BeamPROP photonic device simulation software (Beam Propagation Method)
ANSYS Finite Element Analysis Software
L-Edit mask layout software

Molecular Beam Epitaxy System

Class 10,000 cleanroom designed for semiconductor material growth and processing

MBE demo: Ali & Rajeev MBE

4 class-100 laminar-flow exhaust fume-hoods

Particulate hood; Acid hood; 2 chemical processing hoods

Riber 2300 solid-source Molecular Beam Epitaxy (MBE)

Rough (10-3 torr) pumping system

Pfeiffer XtraDry piston pump; Three-stage cryo-adsorption pumping

3 UHV chambers:

Introduction Chamber

Load-lock introduction
High-capacity CTI-Cryogenics Cryo-Torr 8 cryopump

Analysis Chamber

Riber ion pump

Deposition Chamber

Material sources: gallium, arsenic, indium, aluminum, silicon, and beryllium; 500cc valved arsenic cracker cell
High-capacity CTI-Cryogenics Cryo-Torr 8 cryopump
High-capacity Riber ion pump
Closed-loop liquid nitrogen delivery system
Reflection high-energy electron-diffraction (RHEED)
Mass spectrometer (RGA); Optical Pyrometer
Computer-automated growth and monitoring

The MBE Laboratory was set up thanks to a gift from Prof. Amnon Yariv at Caltech.

Alireza Ghaffari is the engineer who transfered the machine from Caltech to UCSC and installed it at Baskin Engineering Room BE240.

Semiconductor Characterization Lab

We use the following experimental setups for semiconductor device characterization:

Micro thermocouple device thermal characterization

By using a micro thermocouple directly in contact with the device under test, high resolution calibrated thermal measurements are acquired. A temperature controlled stage, or hot plate are used to change the substrate temperature. The test setup is automated using LabView, and the GPIB bus.

Equipment:

50 micron diameter reference, and measurement thermocouples
Precision Cascade and Micromanipulator micro-probes
Temperature controlled stage or hot plate
ILX and Newport current source
Keithley Precision Voltmeter
Dell PC, LabView/GPIB
4 wire nanovolt source meter

Thermoreflectance imaging/ Backside thermal imaging

To see the distribution of heating or cooling in a micro structure, thermal imaging is performed with the thermoreflectance method. Figure in RHS shows the topside setup using visible light, while Figure in LHS is a picture of the backside, through the substrate thermal imaging setup using near IR illumination source.

Equipment:

Thermo Oriel 150W, 100W Hg arc lamps
Thor Labs, New Focus photodiodes
Precision micro-probes
Unidex, Newport Computer controlled translation stages
ILX lightwave Low noise current amplifier, pulsed current source
SRS lock-in amplifiers
SRS optical chopper
Dell PC, LabView, GPIB, Matlab
Olympus, Melles Griot 10x, 16x, 80x microscope objectives
Sony, Toshiba, milliwatt semiconductor laser sources
Thor Labs TEC controlled laser mount
Various in house machined components

Low Temperature Device Characterization

In order to characterize devices at low temperatures two Janis cryostats are used. Figure below shows an image of a cryostat, with samples mounted, and the results of a low temperature thermoreflectance experiment where the mico-cooler performance was measured down to 5K. The cryostats have been used for low temperature I-V device characterization as well as thermoreflectance measurements. In addition, the cryostat allows for optical measurements of samples under a vacuum which is necessary for nano-wire characterization.

Equipment:

Janis cryostat, transfer rod
Turbo pump
Keithley femptoamp source meter
Cold finger temperature controller
Dell PC, LabView/GBIP

Circuit prototyping/Wire bonding

In order to maintain the ongoing experiments, it is necessary to have a circuit prototyping area, as well as a wirebonding machine. In figure below we see the circuit prototyping/ wire bonding bench set up in the lab. Test circuits are interfaced to the computer with National Instruments digital and analog data acquisition boards.

Equipment:

Westbond wirebonding machine
High Speed oscilloscope
Tecktronics ocsilloscope
BNC pulse generator
Dell PC, National Instruments DIO, ATMIO series boards
Various DC lab power supplies
Soldering station
SRS Spectrum analyzer
SRS function generator(s)
Various RF test equipment

Laser characterization

Laser characterization includes IV characteristics, mode profiles, linewidth analysis, temperature dependent wavelength shift, and others. Acquisition of such data is possible with the laser characterization set up. Figure below shows the setup for characterization of multi-section tunable semiconductor lasers.

Equipment:

ILX temperature controller/ Current source
Agilent Optical spectrum analyzer
Hamamatsu IR sensitive camera
Newport Optical power meter
Precision micro probes
Temperature controlled stage

Atomic Force Microscope

Veeco/Digital Instruments Dimension 3100 Atomic Force Microscope is used to measure nanoscale mechanical, electrical, optical, magnetic and thermal properties of surfaces. The versatility of the Atomic Force Microscope is extended to applications of integrated circuits and devices with the addition of a scanning capacitance module (SCM) and NSOM capability. Using the AFM as the base unit, allows simultaneous topology, capacitance and optical measurements.

SCM enables AFM researchers to measure small capacitance variations on semiconductor samples with a high spatial resolution (< 15 nm). A user applies a selectable AC and DC bias between the sample and the conductive tip, with the tip being on virtual ground. The tip and sample form a small metal-insulator-semiconductor (MIS) capacitor, whose capacitance value monitors using a high-frequency resonant circuit while the tip scans in contact mode. In this way, one can obtain an image of the sample’s topography and capacitance variation simultaneously, enabling the direct correlation of a sample location with its electrical properties. An important application of SCM is to measure the two-dimensional distribution of electrical carriers inside semiconductor devices. NSOM enables various optical measurements, Transmission, Reflection, Collection-Mode, Polarization, Fluorescence, and Spectroscopy with sub-wavelength resolution.