November 29, 2011 -- Applied Materials (AMAT) released a new film treatment called Applied Producer Onyx that reduces the power consumption in semiconductor chips while increasing mechanical strength. The product targets the challenges associated with 3D packaging applications and technologies such as copper pillar, 3D stacking, and lead-free soldering.
The solution decreases the dielectric constant value by up to 20%, thereby reducing chip power consumption. After treatment, the sidewalls of the film have been restored to the original bulk state. According to Russ Perry, global product manager, Dielectric Deposition Group, at Applied, the product is available for shipping and multiple pilot production lines are already running.
|Figure 1. Illustration of how Onyx treatment strengthens the chip. *Normalized Young's Modulus. SOURCE: Applied Materials|
Perry discussed the treatment that drives carbon and silicon into the porous dielectric film to reinforce the insulating material at the atomic level (Fig. 1) in a podcast interview with SST.
In the podcast, Perry explained how multiple applications of the treatment enable scaling as the treatment is applied to the interconnect structure after etch and after CMP (Fig. 2). The process of integrating low-k films into the interconnect requires that they be subjected to many harsh chemistries and processes noted Perry. “With onyx, we are able, with the chemistry we have developed along with our chamber design, to take the film that we have now and insert carbon and silicon into the network and drive it deep into the film -- not just at the surface level,” he said.
|Figure 2. Onyx treatment solves k shift. (Estimates based on ITRS roadmap metrics for same film strength.) SOURCE: Applied Materials.
For etching and CMP processes, the wafer is processed after those processes have been done. “After etch, we know the sidewalls of the vias and the trenches are exposed to chemistries from photoresist stripping and wet clean, which can alter the surface and the film around those structures.” Perry further noted that this application will be the first place the new treatment will be used to restore the dielectric constant and toughen up the film. The next application is “after CMP and after copper oxide removal, where the surface of the dielectric film has been subjected to CMP slurries and plasmas that have effectively increased the dielectric constant of the film,” said Perry. “By using the Onx treatment, silicon and carbon are driven back into the network of the low-k film and improve the density of the network for improved mechanical strength."