editor's blog
Subscribe Now

What Makes LEDs Different?

Earlier this month, KLA-Tencor released their ICOS WI-2280 inspection tool for LEDs. Reading through all the things it does and the improvements in provides – things like enhanced recipe qualification and reduced setup time – well, for someone like me who doesn’t spend all his time in this world, you start to think… This sounds like a lot of other inspection tools. And there do seem to be a lot of different tools.

It makes you wonder, why can’t one tool simply do it all? Reading through what the 2280 does, it seems like it would be good stuff for any IC. So I asked that of them as one of those “OK, I feel really stupid asking this, but…” questions, and they clarified both why this is different from other IC inspection tools and what it is not intended to do.

First, and most fundamentally, LEDs use sapphire as a substrate, and it’s transparent. That means that different lighting is required as compared to a silicon wafer. I suppose you could argue that this should then just be a “setting” or adjustment on a more general-purpose tool. But that would fly up against a second concern: cost. The defects being detected on LEDs are in the 3-5-µm range, far larger than what you would look for on a 28-nm chip. No need to burden it with expensive micro-mote detection capabilities.

There’s also one other less obvious difference. LEDs are typically inspected again after dicing. It’s “relatively” easy to inspect dice on a wafer – once you align the wafer, you’re set. But with dice in trays, each die can shift around, so post-slicing inspection requires separate attention that’s not needed for standard ICs.

Meanwhile, the 2280 is intended for all in-line inspections of patterned wafers (or diced wafers). It’s not intended for sampling (which may use a slower, more detailed analysis) or for inspecting the blank substrate.

You can find out more in their release.

Leave a Reply

featured blogs
Jul 6, 2022
With the DRAM fabrication advancing from 1x to 1y to 1z and further to 1a, 1b and 1c nodes along with the DRAM device speeds going up to 8533 for Lpddr5/8800 for DDR5, Data integrity is becoming a... ...
Jul 6, 2022
Design Automation Conference (DAC) 2022 is almost here! Explore EDA and cloud design tools, autonomous systems, AI, and more with our experts in San Francisco. The post DAC 2022: A Glimpse into the World of Design Automation from the Cloud to Cryogenic Computing appeared fir...
Jun 28, 2022
Watching this video caused me to wander off into the weeds looking at a weird and wonderful collection of wheeled implementations....

featured video

Synopsys PCIe 6.0 IP TX and RX Successful Interoperability with Keysight

Sponsored by Synopsys

This DesignCon 2022 video features Synopsys PHY IP for PCIe 6.0 showing wide open PAM-4 eyes, good jitter breakdown decomposition on the Keysight oscilloscope, excellent receiver performance, and simulation-to-silicon correlation.

Click here for more information

featured paper

3 key considerations for your next-generation HMI design

Sponsored by Texas Instruments

Human-Machine Interface (HMI) designs are evolving. Learn about three key design considerations for next-generation HMI and find out how low-cost edge AI, power-efficient processing and advanced display capabilities are paving the way for new human-machine interfaces that are smart, easily deployable, and interactive.

Click to read more

featured chalk talk

TE's Dynamic Series for Robotics

Sponsored by Mouser Electronics and TE Connectivity

If you are designing a robot, a drive system, or any electromechanical system, the dynamic series of connectors from TE Connectivity might be a great solution for your next design. In this episode of Chalk Talk, Amelia Dalton chats with Jennifer Love from TE Connectivity about the design requirements common in robotic applications and why this new flexible connector with its innovative three point contact design, audible locking system, and dedicated tooling make it a great solution for all kinds of robotic designs.

Click here for more information about TE Connectivity Dynamic D8000 Pluggable Connectors