Noncontact Probe System Targets 65-nm Technology
-- Test & Measurement World, 7/18/2005 7:11:00 AM
Suss MicroTec has developed a noncontact probe system that acquires signals from circuits fabricated in 65-nm processes and below without loading the circuit under test. The company demonstrated the system at Semicon West (July 11-15, San Francisco, CA, www.semi.org), where it also exhibited its BlueRay semiautomatic wafer-probe system and the new ReAlign feature for its MicroAlign probing technology.
The noncontact probing system, which targets deep submicron ICs operating at 1 V and below, employs an integral atomic-force probe in combination with a stable prober such as the Suss PM8 to enable deep submicron scanning and positioning. After the tip is positioned above an area of interest, it is stimulated with electrical pulses. The system employs a laser technique to monitor the probe deflection that results from the forces generated between an electrical signal from the DUT and the charged tip. From the measured deflection, system software extracts the DUT signal-voltage waveform, all without contacting the DUT. Signal acquisition operates in free air or through thinned silicon or oxide.
"The noncontact probe system is the only probing technology currently available that enables worry-free in-circuit probing of functional devices, acquires full voltage-level information, and is as easy to use as an oscilloscope," said Dan Ouellette, noncontact probing manager at Suss MicroTec, adding, "In a nutshell, it's in-circuit probing without the load."
The company also demonstrated its BlueRay semiautomatic wafer-probe system for optoelectronic devices, such as LEDs, that require quick and effective test of multiple devices on a single wafer and whose designers employ bonding pads as test pads. BlueRay, according to the company, provides the z-access accuracy necessary to ensure repeatable electrical contact with a DUT while limiting the pad damage that could render a device unusable. The semiautomatic system also optimizes communications between prober and controller to provide the fast cycle times necessary for high throughput.
Finally, the company demonstrated its new ReAlign tool, which complements the MicroAlign technology for the Suss ProbeShield system. ReAlign automatically realigns vertical-probe tips to pads after temperature changes to adjust for thermal drift.
"We are seeing a growing demand for test automation in the characterization labs," noted Axel Schmidt, device and wafer characterization product manager at Suss, in a company press release. He added, "With ReAlign, the often lengthy temperature test cycles that slowly ramp up the temperature of the device under test in order to analyze behavioral changes in the chip can now be performed without repetitive, time-consuming manual readjustment from the engineer."
