full-circle, metal-gates are back

Sometimes the article quality over at EETimes.com makes you wonder whether the writing has been outsourced to a pupil at the elementary school level. Thus, it is nice and refreshing to read an article that is properly researched and well written. Case in point, Don Scansen’s article describing Intel’s 45-nm high-k metal-gate process and the accompanying analysis. As discussed by Don, the breakthrough that Intel has achieved at the 45-nm node is the incorporation of a high-k metal-gate into the process. The high-k material enables Intel to use a thick gate dielectric, which significantly reduces the gate leakage, while maintaining good conductivity through the transistor. Don also reveals that at the 65nm process node, the Intel gate dielectric was 13 percent thinner than the gate dielectric utilized by AMD. This would explain why Intel needed to incorporate a high-k material at the subsequent node, for thinning the dielectric any more was probably not a reasonable option. With the 45nm process Intel is expecting a leakage improvement in the neighborhood of 10x. The article also gives us an idea about the performance that Intel can expect: At 1.3v, I_on for the nfet and pfet are estimated to be 1.66 mA/um and 0.71 mA/um, respectively. The leakages for the nfet and pfet are expected to be 37 nA/um and 45 nA/um, respectively. An interesting observation that Dan makes is that Matsushita/Panasonic actually beat Intel to the 45-nm node using immersion lithography vs. Intel’s dry approach. And while the gate technology utilized by Matsushita is traditional, the immersion technology enables the company to achieve tighter metal pitches than Intel. The article also delves into a brief discussion of the materials utilized as well as about future process scaling, but just in case all this information is not enough to satisfy your technical cravings, you might also be interested in reading an interview with several of the Intel researchers that partook in the development of the process over here.