BILTHOVEN, the Netherlands -- ASM International N.V. here and partner Royal Philips Electronics N.V. announced they have produced what is believed to be the thinnest gate dielectric with a commercially acceptable leakage current.
The thin-film dielectric layer has an effective thickness of 1.1 nanometer--comparable to four-or-five atoms of silicon oxide, in terms of thickness, according to researchers. The thin dielectric layer is also about one million times better than silicon oxide, in terms of acting as an insulator in transistors, according to the two companies.
The gate dielectric was produced with atomic layer chemical vapor deposition (ALCVD) technology and equipment developed by ASM's Microchemistry Ltd. subsidiary. The Dutch equipment supplier acquired the ALCVD operation last year to develop next-generation layering technologies (see Sept. 1, 1999, story).
Philips and ASM said the thickness of the dielectric layer is similar to what will be needed for the 0.07-micron (70-nm) process technology node later in the decade.
"To produce such ultra thin layers, we had to change from silicon oxide to a layer consisting of three elements: zirconium, aluminum and oxygen," said Ivo Raaijmakers, chief technology officer of ASM's frontend operations. He credited ASM's Pulsar ALCVD system with being able to control both the composition and thickness on the atomic level for the extremely thin insulating layer.
Earlier this week, ASM announced it had shipped the first wafers with high-k dielectric film grown from ALCVD to International Sematech in Austin, Tex. Those wafers are part of a joint development program for advanced CMOS transistor gate structures (see Oct. 30 story).