A.3.1:5.1 - Manufacturing recipe

Situation. A fab process engineer must decide whether two current SOP editions describe the same alumina-etch method before either description is cited in a work plan. The engineer needs a reusable method identification.

Reusable way and applicability. Etch_Al2O3 applies to alumina-coated silicon wafers whose substrate class and coating range satisfy RecipeWindow-Al2O3-3, using a qualified PE-4 plasma-etcher family and the gas-mixture range declared by that window. Its generic participants are the wafer surface, qualified etcher, admitted gas mixture, and target-depth parameter. A future enactment holds the admitted pressure and temperature envelopes, adjusts exposure until the declared target-depth stop, and preserves the substrate and maximum-temperature conditions.

Preconditions and stop. The method is applicable only when the wafer material and coating range are known, the selected PE-4 calibration is current for the planned use, the admitted gas mixture is available, and the safety interlocks required by RecipeWindow-Al2O3-3 are part of the intended setup. If the recipe fails to state the material/coating range, calibration requirement, gas mixture, target-depth stop, or preservation limits needed to identify the way, keep alumina etch as a method cue until that meaning is recovered. If a particular wafer or setup fails the stated range or calibration requirement, retain the identified Method and stop that planned use under its applicable admission or gate rule.

Visible identification result. Under effective FabProcessScheme-2026, where Al2O3, target depth, and substrate preservation have the local senses used above, the engineer can write:

MethodRef: Etch_Al2O3
SemanticBasisIfMeaningVaries: FabProcessScheme-2026 (`Al2O3`, `target depth`, and `substrate preservation`)
Applicability: alumina-coated silicon wafer; RecipeWindow-Al2O3-3; qualified PE-4 family
GenericParticipantMeanings: wafer surface; qualified etcher; admitted gas mixture; target-depth parameter
MethodConcern: remove the admitted alumina layer to the declared target-depth stop
Preconditions: material and coating range known; calibration current; gas and safety setup available
IntendedResultOrPreservedCondition: target depth reached; substrate and maximum-temperature bounds preserved

This result lets the engineer compare the two SOP claim sets against one method identity and lets a later work plan cite that method and the selected description edition. The SOP, PLC program, calibration recipe, and supplier note remain U.MethodDescription candidates when A.3.2 identifies what each episteme describes (EntityOfConcern) and the substantive claims it carries. For later work authorization or claims that Work W-143 occurred or Wafer-22 changed or passed metrology, use the relevant A.15.2, A.15.1, A.3.4, measurement, evidence, assurance, or gate pattern.