Title: Modeling semiconductor devices and plasma processes Speaker: Phillip J. Stout, Freescale Semiconductor Date/Time: Thursday, February 16, 2006, 1:00 – 2:00 pm Location: Building 980, Room 95 (Sandia NM) Brief Abstract: The plasma process modeling work uses a suite of computational tools (reactor, feature, molecular dynamic, and lithographic models) to better understand plasma processes. The Monte Carlo feature model in this suite is Papaya. Its job is to collect the information from the other models and predict what the manufactured sub micron feature will look like. Papaya is being used in deposition and etch studies of semiconductor fabrication at Motorola/Freescale. In addition to deposition and etch unit processes, Papaya allows for integration studies. By looking at a sequence of etch, deposition, and lithography steps used in the fab one can understand the interdependencies between steps. This multi-step physics based modeling approach has been used to study physical vapor deposition (PVD) and atomic layer deposition (ALD) processes, the construction of dual inlaid (or dual damascene) structures, to study a gate profile after etching through the different materials in a gate stack, and to study +22 etching, deposition, and masking steps in FinFET construction. A recent innovation is coupling to 3D lithography models, which predict photoresist (PR) profiles. PR profiles are predicted by calculating light diffraction through a photomask and applying PR development models to predict how the PR will develop. The lithography model supplies Papaya with the initial geometry of the PR etch mask. This is important as etch profiles can change with the geometry of the PR mask. Papaya has been used to study the edge movement in SRAM bit cells to see how the etch process alters the PR pattern from the ideal as it is transferred into the poly silicon from the photomask. Knowing how the edges (top down) of the pattern move during etch allows one to adjust for the effect through etch correction at the photomask level and explore new reactor operating conditions or chemistries to minimize the movement. CSRI POC: Robert J. Hoekstra, (505) 844-7627 |