MRAM specialist Spin Memory attracted some important allies as it goes after the U.S. military memory market...
Spin Memory has partnered with ARM and Applied Materials to start making what the Fremont, California-based startup expects to become the first MRAM to win broad adoption in military, automotive and medical equipment.
The eight-year-old company recently closed its series-D round of funding from existing financial and strategic partners that include ARM and Applied Materials, according to Spin CEO Tom Sparkman. The company has built in the United States what is probably the world’s only dedicated MRAM fab and aims to tap trade-war subsidies from the US government in the near future, he said.
“We’re the only US-based MRAM company that can make second-generation MRAM,” Sparkman said in an interview with EE Times. “We can make very small quantities, at least enough for the military.”
Chipmakers such as Samsung, Taiwan Semiconductor Manufacturing Co. (TSMC), GlobalFoundries and United Microelectronics Corp. (UMC) can make planar versions of MRAM. Spin has developed what Sparkman calls a “second-generation” of the memory in a perpendicular configuration that increases density as much as five times compared with planar MRAM.
The company has a portfolio of about 270 patents covering intellectual property that Spin has created to put non-volatile memory (NVM) and SRAM together on a single MRAM die.
“MRAM is a technology that can be very flexible,” Sparkman says. “It can do NVM, and it can do SRAM. You can make it have very high retention and not be very fast or not have a lot of retention but with 10 nanosecond switching. And if you want to put both of those on a die with MRAM, that’s a patent we hold.”
Another patented technology is what Spin calls its endurance engine, which increases the life of the MRAM while at the same time correcting one of the characteristic idiosyncrasies of the memory which is stochasticity.
“You can write MRAM, and it doesn’t always write,” Sparkman says. “There is a finite possibility to do everything perfectly. The one doesn’t change to a zero. But we can detect that. We can find out when it happens, and then and then go and correct those errors.”
Another piece of technology that Spin has is called processional spin current (PSC), which enhances the magnetics and retention of the magnetic tunneling junction (MTJ) that’s a fundamental part of an MRAM. With the proprietary technology added to an MTJ, data retention increases by as much as a thousand times, according to the company.
“Where you would have maybe a week’s retention on an MTJ without our technology, you’d get over a year with our technology,” according to Sparkman.
The technology advancements help to make MRAM competitive with SRAM and flash memory, he says.
The fab Spin currently operates may be small at about 25 wafers per week, but it can meet demand from the US military, according to Sparkman.
“It’s perfect for doing wafer services and of course, prototyping and R&D,” he says. “What we’re proposing to the government is we take that very low capacity and expand it. If we got into hundreds or two hundreds of wafers per week, I think that’s all the government would need from us. That’s the proposal we’re making.”
The company aims eventually to reach a thousand wafers a month, which would be more than enough for US military demand, according to Sparkman. He says there’s a “ton” of demand in the future for MRAM because of its inherent rad hardness that owes to the fact that it’s the first mainstream memory that isn’t based on an electrical charge.
In the long term, Spin plans to be a manufacturer and an intellectual property licenser.
The company is mainly funding itself through licensing. Eventually, Sparkman wants Spin to become a fabless semiconductor company.
“I think what will end up happening eventually is that someone will want this military piece, and we’ll probably spin the fab out either as a standalone entity or sell it to one of the guys who are in that business,” he says. “Then we’ll become a fabless company that is just designing unique products in MRAM.”
The foundries that make MRAM are looking for a good way to implement MTJ technology, he says.
“What we’re doing with ARM is taking existing technologies from these foundries,” he says. “We add our techniques to them. And now you’ve got a robust and what we call a zero-defect MRAM. It’ll pass automotive qualifications and is really as robust as you need it to be.”
The company is working with Applied Materials to provide MRAM technology to foundries that don’t already have it. Together with Applied Materials, Spin plans to sell an MRAM process and provide engineers who can bring the process into production.
Trade war subsidies
Spin is counting on trade-war subsidies for a chunk of the nearly $100 billion that will probably come from the US Congress’s proposed American Foundries Act and the CHIPS Act, according to Sparkman. The company expects to be the sole US supplier of MRAM chips. Even US-based GlobalFoundries is making MRAM in Singapore, Sparkman notes.
“MRAM is very unique in that it’s inherently rad hard,” he says. “The next war is not going to be fought in trenches, it’s most likely going to be fought in the air and probably even in space. This ability to withstand radiation is going to be a big deal.
“There’s a real move now in the United States through the president or Congress or the military to move manufacturing from China back here,” according to Sparkman. “The original reason for us to build a fab was because nothing to do with MRAM existed anywhere else in the world.”