Modeling Proposal:

Working with our manufacturing team a nd evaluating our wafer start and technology profiles, we have determined that we coul d build a model using the following approach:

a. Analyzing our fab wafer production profile s and technologies, we find that we have two technology corridors: al uminum and copper technologies. b. These in turn, can be broken down into several primary technology recipes. The recipes are representative of the overall fabricator routing used for the primary technology recipe.

a. As a logic foundary fab, there are many subcategories of recipes, but they adhere tightly to the primary recipe. i. The main process steps and recipes are consistent w ithin the given technology recipe. ii. Customizations tend to involve th e addition of different memory components which have less levels/complexity and use less gas/cm2, so the primary technol ogy would give a conservative estimate. iii. The IBM BTV fab is likely a worse case example, as it has both aluminum and copper technologies. b. A memory fab or a logic fab buildin g defined products to a defined technology recipe will likely have on ly a single technology corridor and two or three primary technology recipes.

c. Once the primary technology recipes are id entified the routing can be analyzed, the process steps identified, and the PFC gas use for each process step and gas type can be calculated. It will be necessary to as sign an uncertainty to the estimation of the gas use based on the recipe calculation. d. The gas quantities used per wafer pass by t echnology recipe and process step will be cumulated to generate a total gas consumption per wafer start per primary technology recipe type.

e. Gas use will then have to be apportioned to the process type based on records/tool connections/estimates.The data will then be compiled into a tabl e as follows. Each cell would have a value where that process step was used in the primary technology recipe.

Process Type Gas Use by gas type for Time Period (kg) Technology Wafer Count for time period Remote Plasma Clean In-situ Clean Thermal Clean Wafer Clean Etch

Aluminum1 Aluminum2 Copper1

Actual Gas Use

The following data types with specified unc ertainties would need to be developed:

Measurement Variability Apportionment Variability

Process Variability Apportionment of process type by tool Gas Use by Process Type: From Recipe Flowmeter: Recipe vs. Actual use. How variable is the specific
process use Actual Gas Use by Process type: Cylinder Records Tolerances in Scale and heel
measurements Where a single measured source supports multiple process types. Process Emissions Factors Number of samples and variance in each data set. Wafer Count

Uncertainties:

Measurement: Where the measurement device: flow meter or scale will introduce uncertainty into the measured result. Apportionment of process types to a single supply source : Where a single distribution system (cylinder or bulk) s upplies multiple tools with multiple processtypes, the gas use will have to be apportio ned to the different process types connected to that distribution system. Gas Use by Process Type within the recipe: It will be necessary to estimate the uncertainty/variability in the process category around the primary recipe for the process type. (this will be based on the vari ability in the recipe s within the process type – high for etch and low for clean).