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COVER STORY – DESIGN COVER STORY – DESIGN

devices. The significance of these tests lies in their dynamic negative and positive voltages. The company
capacity to detect and rectify potential flaws and has created exclusive and patented techniques to
malfunctions in semiconductor devices before ensure that all the thousands of dies on GaN and SiC
their packaging and delivery to customers. By doing wafers remain in complete contact while preventing
these tests at the wafer stage, manufacturers can arcing in high-voltage situations, especially in
identify and resolve problems at an early stage of fine-pitch geometries.
manufacturing, hence minimizing the likelihood of
defective devices being released to the market.

At the forefront of this technology is Aehr Test
Systems, a global supplier of test equipment used
for the process of burning in and testing integrated
circuits that are used in logic, optoelectronic and
memory applications. Headquartered in Fremont,
California, the company offers a wide portfolio
of products used for testing and burning in
semiconductor devices at various stages, including
wafer level, singulated die and package part form.

In an interview with Power Electronics News,
Vernon Rogers, EVP of sales and marketing at Aehr
Test Systems, provided insights on these innovative
testing methodologies, explaining how they can
assess the quality and reliability of semiconductors,
including emerging WBG materials like GaN and
Wafer-Level Test and silicon carbide.

WBG TESTING SOLUTIONS
Burn-In Advances GaN and frontrunner in the burn-in and semiconductor
Aehr Test Systems is acknowledged as a trailblazer
test sector, possessing a patent portfolio that
Reliability encompasses groundbreaking ideas in fields like
portable WaferPaks and exceptionally parallel testing
capabilities. Recently, the company received an initial
customer order for a FOX-NP wafer-level test and Figure 1: Aehr’s FOX-NP system (Source: Aehr Test Systems)
By Maurizio Di Paolo Emilio, editor-in-chief of Power Electronics News burn-in system (Figure 1) and a FOX WaferPak Aligner
intended for GaN power devices.
Wafer-level burn-in is a crucial step in WBG
Aehr Test Systems disclosed that an initial stress while they are still on wafers. Aehr’s “Our FOX systems employ an innovative combination semiconductor manufacturing. It involves subjecting
customer order for a FOX WaferPak Aligner and cutting-edge technology provides important of thermal control mechanisms and electrical stress the wafers to elevated temperatures and electrical
a FOX-NP wafer-level test and burn-in system geolocation data across the wafer without affecting conditions to perform wafer-level burn-in testing on stresses for a specified period, as defined by the
intended for gallium nitride power devices has been the long-term stability or lifespan of good devices. gallium nitride, along with silicon carbide and other customer’s high-temperature gate bias,
received. The customer, a prominent international It does this by causing early-life failures that would devices,” Rogers said. high-temperature reverse bias, time-dependent
provider of semiconductor devices utilized in power otherwise happen in the field. dielectric breakdown, threshold voltage and other
infrastructure and electric vehicles, further expands Aehr’s unique compact system architecture test specifications.
the roster of significant clients that utilize Aehr’s FOX supports full wafer test and thermal control and
products to conduct wafer-level test and burn-in of Aehr Test wafer handling in a form factor called a “Blade,” “Subjecting each wafer to accelerated stress
wide-bandgap (WBG) compound semiconductors. Systems’ in either a 3.4-inch (8.5-cm) height test for higher conditions, such as elevated temperatures and
It is anticipated that the FOX-NP system, which Vernon Rogers parallelism or a 6.8-inch (17.2-cm) height test increased voltage levels, help uncover latent defects
comprises the FOX WaferPak Aligner, will be delivered for more channels. The FOX platform features a or weaknesses in the devices that might lead to
and set up during the ongoing fiscal quarter. sophisticated thermal control system that offers early-life failures,” Rogers said.
precise cold and hot thermal control to each
Part of the reason the company chose to order a AEHR TEST SYSTEMS wafer. This is achieved by applying electrical stress “The challenge with test and burn-in is to not
system from Aehr was because of Aehr’s ability to Wafer-level test and burn-in is a crucial procedure conditions to each wafer using Aehr’s exclusive exceed the device limitations that can actually
offer a complete solution that lets thousands of in the semiconductor industry to guarantee the precision power supplies and measurement create latent defects, or ‘walking wounded,’ devices,
devices be put under temperature and electrical dependability and excellence of semiconductor instruments, which can generate a wide range of and this requires a careful balancing of electrical,

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