A Full Factory Transient Simulation Model for the Analysis of Expected Performance in a Transition Period
Intel's Fab-18 is based in Israel, and has transitioned from producing 0.18-micron logic devices to producing 90 nM flash products. During this transition period, the factory has de-ramped in volume of logic while ramping-up flash. AutoSched AP software was utilized for the development of a transient simulation model of the Fab's behavior during this period. It is the first attempt, at Intel, to utilize a full factory simulation in order to analyze and support decisions that pertain to a transient period of parallel de-ramp and ramp-up of technologies. Unlike typical simulation models for the analysis of factory performance and behavior in steady-state, the transient model poses several modeling challenges and requires major adjustments in dealing with these challenges. In this paper, we discuss those aspects. The benefits and contribution of such a model to decision making and the improvement of factory performance are also presented
A NEW SIMULATION TESTBED FOR SEMICONDUCTOR MANUFACTURING
We propose the creation of a new set of fab simulation testbeds. Extensions and additional features, not considered in the original MIMAC datasets, shall be incorporated in these new testbeds, thus allowing researchers to evaluate new methodologies with the same frame of reference. To do this, we surveyed the literature and mapped the pertinent research efforts of the past two decades. In this paper, we discuss in detail the various aspects of the new testbeds, in order to receive feedback from the simulation community on the importance of inclusion of some of the items in question; and the verification of the required inclusion of other items. Given the feedback, we aim to generate these testbeds within a year to serve as the new frame of reference for the benefit of the entire semiconductor manufacturing simulation community.
Noctilucent cloud observations over Greenland by a Rayleigh lidar
We report on the detection of noctilucent clouds (NLCs) by a Rayleigh lidar system located on the west coast of Greenland during operations in July and August 1994. The lidar detected NLCs in the zenith on three nights (July 28–29, July 31–August 1, and August 4). The lidar measurements are presented at temporal (1 minute) and spatial (192 meter) resolutions exceeding previously reported lidar measurements of NLCs and reveal significantly more structure in the clouds. Unique cloud features are observed for each night NLCs were detected. Because of the large backscatter ratio associated with NLCs, the volume backscatter coefficient for the cloud particles can be determined more accurately from the lidar signal than the backscatter ratio as the upper mesospheric molecular number density is negligible in the volume backscatter coefficient calculation. The volume backscatter coefficient values determined from the three nights of NLC observations would be classified by current models as moderate to extreme. The extreme backscatter from NLC measurements on August 4 tests the assumptions used in existing models.