Semiconductor Test Laboratory Improvements for High Temperature, Low Temperature, and High Frequency with Electronically Switchable Load

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