May 19, 2008 – ASM International’s US subsidiary, ASM America, says it has a new atomic layer deposition (ALD) process targeting 32nm-node chip manufacturing with lanthanum oxide (LaOx) and aluminum oxide (AlOx) high-k cap layers that enable high-k metal gate stacks using a single metal, instead of two different metals required previously for CMOS.
“Solving the integration challenges for high-k metal gates is a top priority for most of our customers,” explained Glen Wilk, product manager for transistor products at ASMI, in a statement. “This new process greatly simplifies the high-k metal gate integration and allows us to support gate first, as well as gate last process flows.”
The company says it has “patents pending” on the new LaOx and AlOx cap processes. Without cap layers, the two different metals are needed to create desired electrical properties of the p and n portions of the transistor switch. Adding an ultrathin cap film between the hafnium-based gate dielectric and metal gate allows atomic-level charges to affect the interaction between the dielectric and the metal. Metal film performance can be tuned by varying the cap film’s thickness in a range <1nm, the company said in a statement.
The process works with ASMI’s Pulsar module, which can be integrated into the company’s Polygon platform to deposit hafnium-based films and cap layers sequentially (without exposure to atmosphere). ASMI noted that “several key customer locations” are using the new process, with demos available in its applications lab.