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Semiconductor Test Laboratory Improvements for High Temperature, Low Temperature, and High Frequency with Electronically Switchable Load. Group 2 Jomah Fangonilo Shawn Hughes Shawn Sickel Antony Stabile. Dr. Vikram Kapoor Dr. Kalpathy Sundaram.
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Semiconductor Test Laboratory Improvements for High Temperature, Low Temperature, and High Frequency with Electronically Switchable Load Group 2 JomahFangonilo Shawn Hughes Shawn Sickel Antony Stabile Dr. VikramKapoor Dr. KalpathySundaram
High Temperature Semiconductor Testing System JomahFangonilo
Motivation • 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
Objectives and Requirements • 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”
Chromalox A-10 Disc Heater 1.5” x 1.5”)
CN7533 Controller (Relay) • 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
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
Omega SA1-RTD-B • 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
Test Results 300 µA 25° C 50° C 100° C 150° C 200 µA 200° C 100 µA 0 µA 0 V 1 V 2 V 3 V 4 V 5 V High Temperature Test Results
Cryogenic Testing System Sean Hughes
What Temperature is Considered Cryogenic? • 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 Kand Freon refrigerants have a boiling point above 93 K.
Reason for Testing at Low Temperatures • 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
Main Components of Cryogenic Test System • 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
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
Indium Tin Oxide (ITO) • 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
General JFET (2N7000) • 2N7000 is an N-Channel enhancement mode FET • Testing 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) Low Temperature 50K Room Temperature 300K
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
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/software Hardware: Agilent GPIB/USB Interface Software: 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
Power Splitter Results From Device Datasheet: 1 GHz -6.03 dB 2 GHz -5.95 dB 3 GHz -6.12 dB From Acquired Data: 1 GHz -6.104 dB 2 GHz -6.311 dB 3 GHz -6.406 dB
ADS Analysis Using exported .s2p file Datasheet
Microwave Transistor Amplifier Results Data from UCF RF & Antennas Lab: S21 1 GHz 17.125 dB From Acquired Data: S21 1 GHz 17.172 dB
Importance UCF’s High Frequency Testing labs require approval and Graduate Student Assistant accompaniment
Electronically Switchable Load Antony Stabile
Design Goals • Must be portably powered • Assembled on a printed circuit board • Must contain a load indicator • Stable switchable interface • Minimal Cost
Design Specification • 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
Analog Multiplexer • CMOS switches • High attenuation about ~300 MHz • Inductive Relay • High power draw • MEMS Relay • Newest technology, high cost Decision – Omron G6Z MEMS relay
Push Button Interface • 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 cost Decision – RC circuit with Schmitt trigger
State Transition Circuit • Modulo 4 counter • Designed with CMOS logic