New Infinity RF wafer probes are ideal for probing fine pitch aluminum pads, ensuring low, stable contact resistance and minimal pad damage
Cascade Microtech has made significant technological advancements to its popular line of Infinity probes, offering finer pitches (down to 50um), smaller contact area and higher frequency operation (up to 220GHz).
Trends in the semiconductor industry are heading toward smaller, cheaper and higher performance devices.
These trends force the size of probing pads (often located in the shrinking area between IC devices) to be reduced to fit in the limited area, requiring IC manufacturers to accurately probe smaller pads on denser devices.
Cascade Microtech's Infinity probes with finer pitches (down to 50um) and smaller contact area allow manufacturers to accurately probe smaller pads.
They are ideal for probing mixed signal MOS devices for wireless communication applications.
Further, silicon CMOS and silicon germanium technologies have enabled smaller and faster devices that require engineers to test and validate performance up to 220GHz and beyond.
The high-performance waveguide series of Infinity probes ensures accurate and repeatable measurements to 220GHz with pitches ranging from 50 to 150um.
Bias tee options are also available.
These probes are frequently used for semiconductor process characterization and test of ultra-high frequency interconnects and devices such as amplifiers, mixers, oscillators, multipliers and switches used in automotive collision avoidance systems, satellite telecommunications, radio astronomy, spectroscopy, surveillance, and medical imaging.
"As the number of nanoscale devices in the market increases, so does the need for higher frequency probes with smaller contact areas and finer pitches," said Larry Dangremond, product manager, Cascade Microtech.
"Cascade Microtech has established itself as the gold standard in Nano-RF device characterisation by continually developing products to meet the quickly evolving needs of wafer-level microwave technology".
When Cascade Microtech first introduced the Infinity probe in 2002, it set a new standard in measurement accuracy as the only on-wafer probe to offer both high-frequency performance and low and stable contact resistance on aluminum pads, commonly used on silicon wafers.
The Infinity probe combines Cascade Microtech's proprietary thin-film technology with coaxial technology, making it equal or superior to all other probe technologies with respect to return loss, attenuation and crosstalk specifications.
The microstrip transmission lines on the Infinity probe's thin-film tips confine fringing fields more tightly than conventional flexible coplanar tips, and the resulting improved field confinement reduces unwanted couplings to nearby devices or other probe tips, thus increasing RF measurement accuracy.
A precision RF connection to aluminum pads on a wafer is much more difficult than connection to gold pads used in other technologies.
The Infinity probe's outstanding performance on aluminum pads is achieved by optimizing the key probe factors that affect contact resistance: tip contact area, force applied, tip metallurgy and scrub.
The force delivery of the Infinity probe is such that only a small horizontal motion (scrub) is necessary to break through the aluminum oxide to make contact with the pad.
This, coupled with the Infinity probe's non-oxidising tips, ensures minimal pad damage and superior contact on silicon devices with pads as small as 25x25um.
