RAPID THERMAL MULTIPROCESSING FOR A PROGRAMMABLE FACTORY FOR ADAPTABLE MANUFACTURING OF ICS

This paper presents an overview of research at Stanford University on the development of concepts of a programmable factory, based on a new generation of flexible multifunctional equipment implemented in a smal ler flexible factory. This approach is demonstrated through the develo pment of a novel single wafer Rapid Thermal Multiprocessing (RTM) reac tor with extensive integration of sensors, computers and related techn ology for specification, communication, execution, monitoring, control , and diagnosis to demonstrate the programmable nature of the RTM. The RTM combines rapid thermal processing and several other process envir onments in a single chamber, with applications for multilayer in-situ growth and deposition of dielectrics, semiconductors and metals. Becau se it is highly instrumented, the RTM is very flexible for in-situ mul tiprocessing, allowing rapid cycling of ambient gases, temperature, pr essure, etc. It allows several processing steps to be executed sequent ially in-situ, while providing sufficient flexibility to allow optimiz ation of each processing step. This flexibility is partially the resul t of a new lamp system with three concentric rings each of which is in dependently and dynamically controlled to provide for better control o ver the spatial and temporal optical flux profile resulting in excelle nt temperature uniformity over a wide range of process conditions name ly temperatures, pressures and gas flow rates. The lamp system has bee n optimally designed through the use of a newly developed thermal simu lator. For equipment and process control, a variety of sensors for rea l-time measurements and a model based control system have been develop ed. The acoustic sensors noninvasively allow a complete wafer temperat ure tomography under all process conditions-a critically important mea surement never obtained before. In an exemplary demonstration of multi processing, we have integrated three different processes with disparat e process conditions-cleaning, thermal oxidation and CVD of silicon-se quentially in-situ. This technology integrates an entire MOS capacitor stack into one process chamber as opposed to three stand alone pieces of equipment needed in conventional technology. This will result in r educed cost of the factory, reduction in cycle time and may provide be tter device characteristics, since the interfaces between the semicond uctor, gate dielectric and gate electrode are free of contamination fr om the room ambient. In general, adaptable manufacturing systems (AMS) based on this approach may offer more economical small or large scale production, higher flexibility to accommodate many products on severa l processes, and faster turnaround to hasten product innovation.