1. Radiant Technologies, Inc. Ferroelectric Test & Technology
August 10, 2018

2. Radiant Technologies
Focus on non-linear electromechanical materials technology. Radiant
Designs and manufactures test instruments and their operating procedures for the world materials market
Fabricates thin ferroelectric film devices
Integrates the two disciplines to create a unique synergy

3. Electrical Test, PAINT, & DLTS
Test Instruments
Electrical Test, PAINT, & DLTS
E31
Radiant pioneered ferroelectric test with the development of the first commercial test system in 1989 and now makes a variety of testers and fixtures.
Magnetoelectrics
AFM Test

4. Cryogenics
Quantum Design PPMS
Lakeshore CRS-EM-HF

5. pMEMS Impulse/Resonance

6. Reliability

7. Test Instrument vs Integrated Ferroelectrics
What follows is a series of measurements demonstrating the properties of Radiant’s thin PZT capacitors measured with Radiant test equipment.

8. IC Scale Cryogenic Testing
Lakeshore CRM-EM-HF

9. IC Scale Cryogenic Testing
0.25m-thick PZT from 10 K to 310 K

10. Quantum Design PPMS P450
The QD Model P450 Multifunction Probe can test disc-shaped bulk capacitors at high voltage down to 2.4 K. B

11. Bulk Capacitors vs Temperature
Many surprises await at lower temperatures.
The sample to the right is a commercial piezoelectric PZT from CTS Wireless in Albuquerque measured in a PPMS that indicates a normal hysteresis loop at room temperature but unexpectedly has no remanent polarization at 100 K.

12. Leakage vs CV vs Remanent Polarization
Decomposing the hysteresis loop on a probe station.

13. High Voltage Polarization & Piezeoelectric Loops
Bulk Capacitor displacement at high voltage and elevated temperature.

14. Thin Film Polarization & Piezeoelectric Loops
The laser vibrometer can measure the piezoelectric motion of a thin ferroelectric film capacitor

15. Thin Solid Capacitor Piezo Loop
AFMs work too. Surface piston of the 1µm-thick PNZT at 25 volts and 500 hertz using an AFM. The capacitor is clamped by the substrate.

16. Thin Film PZT on Cantilever
Capturing e31 for a thin film on a cantilever surface is a 3rd technique.

17. Integrated Ferroelectrics
Radiant has its own cleanroom with a fully integrated thin PZT film capacitor fabrication process.
Devices from that process are inside each Radiant tester.
Reference devices for AFM thin film hysteresis, AFM pMEMS displacement measurement, and Magnetoelectric charge generation are provided with Radiant instruments and accessories.

18. Integrated Ferroelectrics
The Radiant test equipment is used for process control and improvement in the cleanroom.
The test procedures developed in the cleanroom go back into Vision for use in all Radiant tester customers.
Radiant’s test equipment would not be what it is today without this integrated capacitor process.

19. Solid State PZT Capacitors
Radiant Technologies has been fabricating thin PZT capacitors since 1990.
Radiant has been packaging fully integrated thin PZT film capacitors since Packaged capacitor pairs are installed inside Radiant’s commercial testers for use as references.
1992
2004
2008

20. Thermal Silicon Dioxide
Capacitor Structure
Radiant uses a capacitor stack unlike any other. FE
TE VIA
ILD M1
BE VIA
PZT Passivation
Substrate
Thermal Silicon Dioxide
MIRROR

21. Radiant Technologies Integrated thin-ferroelectric-film capacitors.
Radiant has developed a manufacturable process for discrete ferroelectric capacitors.
Radiant inserts packaged capacitors into its testers as test references.
Radiant processes thin PZT film wafers and devices for researchers studying non-linear materials.

22. Ferroelectric Transistor Operation
PZT
InOx
Source & Drain
Gate

23. Membrane Capacitors
A three micron membrane with an embedded 1m-thick PNZT capacitor.

24. Membrane Capacitors
Remanent strain can be measured with Radiant test equipment.

25. Mechanically Coupled Capacitors
1.2mm
DRIVE
RETURN
GND
Sensor
Actuator

26. Complex Cantilevers

27. 1 mm2 Membrane White Light Numarski
A 1-square-millimeter capacitor with the majority of its surface as a membrane. In white light the membrane looks smooth but in Numarski the membrane is unmistakable.

28. 16mm2 Membrane
A 16 square millimeter membrane soldered directly to a PCB with an on-board charge amplifier that connects to the Radiant EDU educational tester using telephone cable.
Pyroelectric constant is -22nC/cm2/K.
The membrane is too fragile to be touched by a human.

29. Ferroelectrics In-circuit
Packaged devices are now being tested as components in electrical circuits with resistors, capacitors, and transistors.
Some are sensors.
Some are memories.

30. Type AB Packaged PZT Cap
Top view
COMMON
CAP A
CAP B
CASE
Cap A
Cap B
Common
TO-18 Can
 Temperature Range: -55°C to 125°C. Do not exceed 125°C.
Maximum Test Voltages: V
Structural Specification:
“AB” Å thick undoped 20/80 PZT with platinum electrodes
Part Number Capacitor Area Color Total PZT Lead Content per Die:
RTAB ,000µ2 BLUE 1.7 micrograms
RTAB403 40,000µ2 ORANGE
RTAB103 10,000µ2 WHITE
RTAB402 4,000µ2 YELLOW
RTAB102 1,000µ2 BLACK
RTAB µ2 RED
RTAB µ2 GREEN

31. Type AB Packaged PZT Cap
The green square in the diagram represents the geometry of the actual capacitor. It is passivated with a 230nm-thick silicon dioxide layer. The original version of this device had a metal contact over the top of the capacitor area. That contact has now been removed to present a silicon dioxide surface. If the metal square is present, do not use it as an electrical contact because it might be shorted to the top electrode.
0.5 cm
1 cm
The solder pad metallization is a stack of a thin chromium adhesion layer, thick copper, and a flash of gold to prevent corrosion of the copper in the atmosphere.
3.980mm
2.000mm
0.620mm
Silicon dioxide surface.
Piezoelectric and Pyroelectric Constants: (room temperature)
d33 60 to 90 pm/V
d31 approximately 30 pm/V
e31 -9 C/m2
p pC/cm2/K
Temperature Range: -55°C to 125°C.
Composition: 10,000Å thick 4% niobium doped 20/80 PZT (4/20/80 PNZT)

32. FerroMEMS Website

33. Radiant EDU
A small ferroelectric tester for the teaching laboratory.

34. Autonomous Memory
Uses the natural memory of ferroelectric materials to force a discrete digital latch to power up in its last state: a single bit of non-volatile memory.

35. Event Detector Autonomous Event Detector Autonomous Memory
Ferroelectric Capacitor
Input Overvoltage
Protection
Output Buffer
Autonomous Memory
Event Input Line

36. Reliable NV Solid State Switch

37. NV-SSS on PCB - Tested
This entire PCB with discrete components and a packaged ferroelectric capacitor can be shrunk into the same solid state switch package on the PCB in the left image. This circuit stands alone and resists disturbs from dramatic power-line voltage events.

38. “A Simple Ferroelectric Memory”
Nuts & Volts Magazine
“A Simple Ferroelectric Memory”
February 2015 Issue
EETimes.com – “Memory 101: What you need to know about FRAM” February 12, 2013