Building flash memory for automotive is not straightforward. Just look at the specs you have to meet for grade 1 qualification:
- 100,000 cycles of endurance (writing new values)
- 10 years data retention
- all at 125°C (also needs to work down to -40°C)
GlobalFoundries have been working with Silicon Storage Technology (which is a wholly-owned subsidiary of Microchip) on non-volatile memory for a decade (that would be longer than GF has been in existence, but Chartered had a long history before they were acquired). They started at 0.35um, then had memories at 0.13um. Now they have announced the latest version in 55nm. The details are that the the two companies:announced the full qualification and availability of SST’s 55nm embedded SuperFlash non-volatile memory on GF’s 55nm Low Power Extended (LPx)/ RF enabled platform. The qualification of GF’s 55nm, split-gate-cell SuperFlash technology-based process was performed according to JEDEC standards. This process technology also met the requirements of AEC-Q100 Grade 1 qualification with an ambient temperature range of -40°C to 125°C, and demonstrated endurance of 100K program/erase cycles with more than 20 years of data retention at 150°C.
So it looks like they are officially qualified at grade 1 but also meet the more stringent requirements of grade 0 (don’t you like the numbering system?) which requires data retention for decades at 150°C.
I had a call earlier in the week with Kevin Yang (who was in Singapore) and Jeff Darrow (on the east coast) of GF, and me, at 7am half-asleep in California. They told me that the bit-cell is tied as the smallest in the industry. The maximum sized macros that they have off-the-shelf is 16Mb (2 megabytes) but there is no fundamental limitation on them going up to 4 megabytes, just that the current target market segments don’t require such large memories. The 55nm process is manufactured in GlobalFoundries’ Singapore facility, I am assuming in fab 7 which is 300mm.
But this non-volatile memory is not just targeted at automotive, it is well-suited to a wide range of applications and they have created a portfolio of macros optimized to different segments such as smartcard, microcontroller, NFC, wearables and IoT. Smartcards in particular are a high-volume user of flash technology although obviously they don’t actually require such high temperature qualification. You want a 125°C credit card in your pocket? I didn’t think so. You probably aren’t going to keep a credit card for decades either.
However, automotive is a big market. According to IHS, the automotive semiconductor market is forecast to reach $31B in 2015, up 7.5% on 2014. Embedded Flash-based semiconductors are a key component of this market segment. For this market the long lifetime and large temperature range is essential. Cars can last at least ten or even twenty years, and they have to work in the middle of winter in Canada and in the middle of summer in Arizona. Data retention (and lots of other things) becomes more of a problem the higher the temperature, and it can get really hot under the hood of a car, so the high temperature is not just an academic number in a SPICE deck but a genuine requirement.
In April, GF also announced a flash memory with NXP based on their 40nm process which will also be manufactured in Singapore. However, this is a collaboration with NXP and is an NXP-specific offering. So while the two offerings both show GF’s ability to bring eNVM to production, the two are complementary.
GF’s 55nm LPx/RF platform, complete with eNVM technology, is available to customers now. Flash cars with flash memories.
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