Simulations of consecutive diffusion process
Process simulation based on virtual reality can comprehensively present the real process on the computer. It can play an important role in the development and manufacturing field of diffusion furnace. This paper researches the establishment of consecutive diffusion process and the key techniques of process simulation. In the process of creating process simulation, V code would be created to control motion of each part. A simulation that reflects on the real process could be acquired with this research. This process simulation not only shortens the development time of diffusion furnace, but also makes designer have a perspective to the defects of product in the design process. It promotes the effective of design, and reduces changes in later period of design.
Diffusion furnace dopant activation matching through a ramped temperature idle
Significant non-uniform 'time at temperature' or Dt variation is observed across a horizontal furnace load in diffusion batch processes. Non uniform activation of dopants is observed in 800degC, short duration processes with high mobility dopant species. Dt matching across the furnace is obtained by changing the temperature zone set points at furnace idle prior to pushing and processing a full wafer batch. A ramped idle temperature ranging 120degC across the furnace improves activation uniformity. Boron implanted test wafers show an 85% reduction in activation non uniformity across the furnace when using a ramped idle.
Mathematical Modeling of Scour and Deposition
Electronic computers are opening up the field of sedimentation engineering by permitting the analysis of problems which heretofore have required too much time and effort. Movable stream bed profiles are being calculated in addition to water surface profiles. The initial gradation of sediment material in the stream bed may be prescribed to facilitate the calculation of an armor layer. This gradation is continually changed by the computer program in response to sediment particles being deposited on the stream bed and material on the stream bed being removed to satisfy transport capacity. Hydraulic sorting of sediment by grain size is accomodated. The stream bed does not have to be represented by a single grain size. Retardance of motion because of armor layer is calculated.