Obducat Rolls Sindre for Patterned Media
David Lammers, News Editor -- Semiconductor International, 7/7/2008 9:47:00 AM
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A new competition is emerging in the nanoimprint lithography (NIL) space between Obducat AB (Malmö, Sweden) and Molecular Imprints Inc. (MII, Austin, Texas). The two companies are competing to supply nanoimprint systems to the hard disk drive (HDD) media vendors. The HDD industry is moving to media (disks) that use discrete track recording (DTR), with the concentric tracks patterned by specially configured NIL systems. After DTR, HDD makers will pattern disks with pillars of magnetic media at ~20 nm pitches. These “patterned media” represent a volume opportunity for the NIL vendors, one that MII claims could reach hundreds of systems.
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| Patrik Lundstrom, CEO, Obducat |
“We have been active in patterned-media HDD since 2001,” Lundstrom said. “We have both the e-beam and NIL technology, which means that we have the capability to produce the stampers [templates] with the right dimensions and repeatability. Our e-beam systems are designed for the rotational patterns in optical and HDD media.”
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| HDD vendors are moving to patterned media, eventually storing bits in ~20 nm pillars of magnetic material. |
“Where we came from in the beginning, we realized that NIL is a replication technology. Without the capability to produce the master, there is no need for the NIL part,” he said. “Producing the master template, that is where the real challenge is. That is where we have a unique position. We have been dealing with the stamper technology since the mid-1990s, and that is where we feel we are one of best.”
The other major challenge is to meet the productivity requirements of the HDD media industry of 1200 disks per hour, which means the systems must be able to print on both sides of a disk at high throughputs.
Lundstrom said Obducat’s Sindre HDD system is capable of 600 disks per hour; the HDD media vendors would use two Sindre systems on each production line. The volumes are large. “If the trend makers are correct, patterned media will account for probably 1.5 billion substrates in five or six years,” Lundstrom said.
Contamination advantage
The Obducat NIL approach uses an intermediate polymer stamp (IPS), which avoids the contamination and particles common with wet resist dispenses, according to Lundstrom. “That approach runs the risk of a lot of contamination.”
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| Obducat transfers the pattern from the template to an intermediate polymer system (IPS). The pattern is hardened with simultaneous thermal and UV (STU) energy. (Source: Obducat) |
The IPS approach transfers the disk pattern from the main stamper to a polymer sheet, which is used one time to imprint on the final substrate. IPS boosts throughput by simultaneously imprinting the disk from both sides, rather than as a sequential step. “IPS is enabling us to have a higher efficiency in each head,” Lundstrom said. “IPS also solves contamination problems: we don’t run the risk of repeating the errors. If we have a particle [on the IPS] we don’t repeat it. And it enables us to use a non-liquid resist, which we imprint on the final substrate.”
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| The use of an intermediate polymer reduces contamination and prolongs the life of the master template, according to Obducat. |
The IPS approach simultaneously employs both thermal and UV energies. “We use a slightly controlled temperature to avoid any thermal issues we would have otherwise [with a room temperature system],” he said. “We have a constant temperature throughout the imprint cycle, and we combine that with UV for fast curing.”
While MII uses a liquid resist, Lundstrom said Obducat’s use of an intermediate polymer involves “a different resist which can use either spin coating or spray coating, or a dip-and-spin technology to apply to the substrate. The disks are dry when we process them, and that is why they don’t attract all the particles that MII’s system does.”
Asked whether the Obducat approach of an intermediate polymer raises the consumables cost, Lundstrom said the IPS material is a very cost-efficient material. “The lifetime of the main stamper is much, much longer with our approach. Making a replica of the main stamper into the IPS material is a very gentle process that gives the customer a long lifetime for the main stamper. That is key, because the main stamper is where the cost is. That is what can drive your cost of ownership through the roof.”
Cost-of-ownership challenge
MII claims that its imprint approach will be less expensive because it does not require an intermediate polymer sheet. Obducat argues that the IPS approach will reduce contamination and prolong the life of the template. “Everybody assumes a $1 cost per disk initially, which very quickly will be driven down to the range of 30 cents per disk. That 30 cents level is when we will reach a fairly high penetration level,” Lundstrom said. “What we discuss with our customers is the total cost of ownership.”
Delivery of the first Sindre HDD system is scheduled to the first half of 2009, to compete with MII’s high-volume HDD imprint system, the Imprio 2200. The Sindre system is priced at ~$6M.
Recently, Obducat announced that it received a purchase order from an unidentified HDD maker for a mass-production imprint system capable of 600 substrates per hour. Lundstrom said the customer also will rely on Obducat for delivery of the e-beam system required to produce the template. “What is key is that we also have the capability internally for these masters. The capability to produce these masters is very important, and very tough,” Lundstrom said. The requirements include a sub-80 nm pitch, with minimum feature sizes in the range of 25 nm. “We can do that already,” he added.
With about 60 employees, Obducat relies on Canon Marketing for its Asian sales and support. “We work with the group at Canon Marketing that sells the Canon lithography equipment,” Lundstrom said. Asked if Canon will manufacture the Sindre HDD systems when the HDD vendors require multiple systems in the near future, he said, “We have strong backing from Canon, but on that point I don’t want to comment.”
