One of the great things about the semiconductor industry is that productivity improvements come in so many forms. At the 45-nm node, productivity requirements are changing, particularly for the dielectric layers.
Novellus Systems is claiming its newest PECVD tool delivers a 40 percent productivity improvement, even as it delivers the longer wafer heat-up times required for accurate thin film deposition.
The Vector Express tool, introduced at the Semicon China show this week, extends the Vector multi-stage architecture to heat up the wafer on one pedestal, reserving the other three stages for deposition. The longer heat-up time allows improved temperature control. The tool supports better degassing of the porous low-k dielectrics that are coming into use at the 45-nm node.
Tim Archer, senior vice president and general manager of Novellus’ Dielectric Business Group, said 45-nm chips are impacted by smaller particles, in the range of 0.08 microns to 0.16 microns in size. And there are more thin film layers, some 38 layers of less than 1,000 Angstroms – including spacer oxides, TEOS, silicon nitride stressors -- and another 18 thicker (>1,000 Angstroms) layers, including the low-k dielectrics.
The Vector Express tool delivers 40-Angstrom repeatability – critical for ultra low-k dielectrics, and control of 1 Angstrom. Some companies will move to the porous dielectrics in order to reduce the bulk k-value to the 2.5-2.6 range, while other vendors will stick with dense films but reduce the thickness, Archer said. At the 45-nm node, the goal is to hit an effective k-value -- including the diffusion barrier layers -- of less than 3.
Strain is more important at the 45-nm node as well, with higher tensile and compressive strain and “other beneficial effects” induced by the PECVD nitride layers, Archer said.
The Vector Express tool has the same challenge as other parts of the equipment chain: a higher technical bar, at higher productivity.
“At each technology node we are trying to squeeze as much throughput as possible, without negatively impacting the process,” Archer said. That nicely sums up why the chip industry is so challenging, and so interesting.
After several quarters of beta testing at various customer sites, Vector Express moves to commercial availability next quarter.
About weQuest: weQuest's are written by G Dan Hutcheson, his career spans more than thirty years, in which he became a well-known as a visionary for helping companies make businesses out of technology. This includes hundreds of successful programs involving product development, positioning, and launch in Semiconductor, Technology, Medicine, Energy, Business, High Tech, Enviorntment, Electronics, healthcare and Business devisions.