Semiconductor Test Laboratory Improvements for High
Temperature, Low Temperature, and High Frequency with
Electronically Switchable LoadGroup 2
Jomah FangoniloShawn Hughes
Shawn SickelAntony Stabile
Dr. Vikram KapoorDr. Kalpathy Sundaram
High Temperature Semiconductor Testing
SystemJomah Fangonilo
Specifically – to add additional testing capabilities to the existing lab setup◦ Current setup only allows for tests under room
temperature In general – many applications exist in the
fields of environmental testing, performance improvement, failure analysis
Motivation
To implement a user-friendly high temperature test system similar to the existing room temperature system.
Main Requirements◦ Capable of testing devices up to 250° C◦ Accuracy of ±1.5° C
Derived Requirements◦ Powered by 120 VAC 50/60 Hz◦ Controller output ≤ 5A◦ Surface measurements ≤ 1.5” x 1.5”
Objectives and Requirements
System Block Diagram
Thermometer
Probe Station
Power SupplyHeater
Data Acquisition SystemController
User
Chromalox A-10 Disc HeaterOutside Diameter
Inside Diameter
Thickness Volts Watts
Watts per Sq. In.
Approx. Net Wt.
3" 0.875" 0.25" 120 300 18 0.3 lb
1.5” x 1.5”)
100-240 VAC 5A load max 3-wire Pt100 RTD or
Thermocouple PID control
◦ Ramp/Soak Free software RS485 28,400 baud max Cost efficient
CN7533 Controller (Relay)
Speco RS232 to RS485 Converter DB9 female connector for
RS232 to two wire Terminal Block for RS485
Auto switching baud rate, speed up to 115,200 baud over a distance of 3,900 ft.
Two wire, different signals, half duplex
Passive operation Units connected together in
RS-485 multidrop operation RoHS compliant.
$30.80
100 Ohm Thin Film DIN Platinum Class “B” (±0.12 Ohms, ±0.30°C at 0°C) Accuracy Standard ◦ ±1.5° C at 250°
Silicone Adhesive rated to 260°C (500°F)
Temperature Range; -73C to 260°C Continuous, 290°C (554°F) Short Term Operation When Installed with OMEGABOND Air Set Cements
Sold in Convenient 3-Packs ($95) Relatively low cost compared to
other RTD and thermocouple options
Omega SA1-RTD-B
Test ResultsHigh Temperature Test Results
300 µA
200 µA
100 µA
0 µA
0 V 1 V 2 V 3 V 4 V 5 V
25° C50° C
100° C150° C
200° C
Chromalox A-10 Disc Heater $0 CN7533 Controller $97 CN7533 Controller Software $0 Speco RS232 to RS485 Converter $30.80 Omega SA1-RTD-B (3-pack) $95 Male-Male BNC Connectors $9.55 Miscellaeous (Wires, terminals, etc) $10 Total $242
Budget
Cryogenic Testing System
Sean Hughes
Two different theories of when this temperature reached.
Most scientists agree that when scale refrigeration ends, cryogenic temperatures begin, which happen at -240 °F ( -150 °C or 123 K)
The National Institute of Standards and Technology at Boulder, Colorado have chosen this point to occur at -180 °C (93.15 K) because the boiling point of gases (such as He, H, O, N) lie below 93 K and Freon refrigerants have a boiling point above 93 K.
What Temperature is Considered Cryogenic?
Industries often tests devices at Extreme Temperatures◦ Largely due to environmental conditions
Electronics operate at increased rates at low temperatures◦ MOSFETs
Increased gain and speed at lower input voltages Less Current Leakage
Semiconductors Characteristics Change at Extreme Lows◦ Freeze-Out – Silicon in the MOSFET begins to break down and
there will no longer be a connection between the gate and the other components of the device and can happen at 80K
Reason for Testing at Low Temperatures
CTI-Model 22 Refrigerator with Janis Research Co. Cold Head
CTI-Cryogenic 8001 Controller and 8300 Compressor
Polyscience 6706 Recirculating Chiller GE Vacuum Pump Temperature Controller
Main Components of Cryogenic Test System
CTI-Model 22 Refrigerator or Cold Head
Cold Head – Houses Semiconductor device, or any other packaged device being tested. Provides a environment capable of temperatures between 10K – 20K.Device is wired to the platform via copper probes to connect to external testing equipment.• 4145B Semicond. Parameter
Analyzer• 4142A Impedance Analyzer• 577 Curve Tracer
8001 Controller / 8300 Compressor
• The 8001 Controller basically acts as a power supply, providing 208V/220V, 30A, 1-Phase to the 8300 Compressor and the Cold Head. NEMA: L6-15R electrical supply.
• The 8300 Compressor provides 99.999% pure compressed Helium
• Helium is mixed with oil to raise its specific heat during compression
• Oil impurities are filtered from High pressure helium
• Pure helium is delivered to the Cold Head, then returns to the compressor
• During the process of compressing helium, heat is generated which is removed by cooling water from Chiller
PS 6705 Recirculating Chiller
• 2 gallon capacity cooling water (tap)• Cooling water cycles through the 8300 Compressor,
dissipating excess heat• Water into compressor: ~70°F• Water out: ~80°F• ~1.67kW of energy removed
• Accomplished by fans passing air over aluminum fins.
• 208/220V 20A, 1-phase NEMA:6-30P
Aluminum Doped Zinc Oxide [ZnO:Al]
• Tested resistivity at temperatures ranging from ~300K down to 60K, samples proved to have poor thermal stabilityat low temperatures Temperature (K) Mega Ohms (MΩ)
300 3.906200 15.944130 26.971117 30.010100 40.72160 119.557<60 Error
High Thermal Stability ◦ Maintained resistance when testing samples from
300K down to 20K◦ Resistance ranged from 54.211Ω at 300K to
57.747 Ω at 20K
Indium Tin Oxide (ITO)
General JFET (2N7000)• 2N7000 is an N-Channel enhancement mode FETTesting at low temperatures show an improvement in performance.• Vgs stepped from 3V to 10V
Room Temperature 300K Low Temperature 80K
N-Channel MOSFET• Increase in Drain Current with the same Gate Voltage applied,
leading to an increase in transconductance from 300K (pictured left) to 50K (pictured right)
Room Temperature 300K Low Temperature 50K
High Frequency Testing System
Shawn Sickel
Goals:◦ Complete interface to Data Acquisition System◦ Export the data in a compatible format for further
analysis in Advanced Design Systems (ADS)
Specification:◦ Read High Frequency Response within the
range of 130 MHz to 18 GHz
HP 8720B Vector Network Analyzer
Block diagram
Specifications of VNA 20+ years old RF range of 130 MHz to 20 GHz Incident power level from -10 to -65 dBm Dynamic range of 85 dB Needs to be calibrated before each use
RF Devices
Power Splitter / Combiner
High Pass Filter Microwave Transistor Amplifier
S-Parameters Definition: The characteristics of the
electrical behavior of a device or change in medium
Used to find the relationship between incident and reflected power waves, and the distribution or splitting of power
Important for device operation
Analysis Logarithmic Magnitude Phase Time Delay Smith Chart Polar Linear Magnitude Real SWR
Interface hardware/softwareHardware: Agilent GPIB/USB InterfaceSoftware: Agilent I/O Suite 15.0
Data Acquisition Software Developed from scratch in visual basic Used to operate the instrument as well as
gather data
Calibration Menu and Options
Calibration Menu Continued
Acquire Data Menu
Acquire Data Menu Continued
Power Splitter ResultsFrom Device Datasheet:
1 GHz -6.03 dB
2 GHz -5.95 dB
3 GHz -6.12 dBFrom Acquired Data:1 GHz -6.104 dB
2 GHz -6.311 dB
3 GHz -6.406 dB
ADS AnalysisUsing exported .s2p file
Datasheet
Microwave Transistor Amplifier Results
Data from UCF RF & Antennas Lab:S211 GHz 17.125 dB
From Acquired Data:
S211 GHz 17.172 dB
Microwave Transistor Amplifier Results Continued
ImportanceUCF’s High Frequency Testing labs require approval and Graduate Student Assistant
accompaniment
Electronically Switchable Load
Antony Stabile
Must be portably powered Assembled on a printed circuit board Must contain a load indicator Stable switchable interface Minimal Cost
Design Goals
Must switch between at least four loads 50 ohm matched impedance Cut-off frequency greater than 2 GHz Coaxial connection to connect to spectrum
analyzer
Design Specification
Design Components
CMOS switches◦ High attenuation about ~300 MHz
Inductive Relay◦ High power draw
MEMS Relay◦ Newest technology, high cost
Decision – Omron G6Z MEMS relay
Analog Multiplexer
Need for stability◦ Switch must be debounced◦ RC circuit
Low quality◦ RC circuit with a Schmitt trigger
Mid-range quality◦ Integrated Circuit Solution
Highest quality, high costDecision – RC circuit with Schmitt trigger
Push Button Interface
Modulo 4 counter Designed with CMOS logic
State Transition Circuit
LED indicators◦ Simplest design◦ Show physical location of active load◦ Requires a demux/decoder
Seven Segment Display◦ Shows load number, which may be referenced◦ Designed from CMOS logic
Decision – In order to minimize the size of the board, only the seven segment display will be implemented.
LED Display
Schematic of Seven Segment Display
Input select lines come from state transition circuit.
Output lines go to inputs of a seven segment display.
Logic Gates and Relays require 5V supply Power Supply must be stable, since the
voltage applied affects relay attenuation. LM2575 Voltage regulator
◦ Requires input voltage greater than 7.5V◦ Provides steady output of 5V
Decision – LM2575 Voltage regulator with 9V battery
Power Supply
Microstrips are printed directly onto the board.
Used to transmit between various relays/coaxial connectors
Board must have a high dielectric strength to avoid signal attenuation.◦ FR-4◦ Rogers RO4003
Decision – PCB with FR-4 Dielectric
Printed Circuit Board
Parts and Cost SummaryItem Unit Price Quantity Cost
G6Z-1PE High-Frequency Relay $6.15 6 $36.90
LM2575 5V Voltage Regulator $3.26 1 $3.264584 Hex Schmitt Trigger $0.71 1 $0.714070 Quad XOR Gate $0.77 1 $0.774071 Quad 2-input OR gate $0.51 1 $0.51
4081 Quad 2-input AND gate $0.50 1 $0.504013 Dual D-type flip-flop $0.51 1 $0.51Inductor, 330 uH $1.33 1 $1.331N5819 Shottky Barrier Rectifier $0.54 1 $0.54SMA Female Coaxial Connectors $3.19 10 $31.90Seven-Segment Display $3.24 1 $3.24PCB Pushbutton Switch $1.36 1 $1.36Printed Circuit Board $33.00 1 $33.00Total Cost: $114.53