Methods for matching semiconductor processing chambers using a calibrated spectrometer are disclosed. In one embodiment, plasma attributes are measured for a process in a reference chamber and a process in an aged chamber. Using a calibrated light source, an optical path equivalent to an optical path in a reference chamber and an optical path in an aged chamber can be compared by determining a correction factor. The correction factor is applied to adjust a measured intensity of plasma radiation through the optical path in the aged chamber. Comparing a measured intensity of plasma radiation in the reference chamber and the adjusted measured intensity in the aged chamber provide an indication of changed chamber conditions. A magnitude of change between the two intensities can be used to adjust the process parameters to yield a processed substrate from the aged chamber which matches that of the reference chamber.

A set of original model candidates are first divided into groups of original model candidates. Child model candidates are generated by performing crossover on each of the groups of original model candidates without mutation. From the original model candidates and the child model candidates, a set of new model candidates are derived, which includes: selecting a group of new model candidates from each group of the original model candidates and the corresponding child model candidates, selecting an additional new model candidate if adding the additional new model candidate increases overall diversity, and performing niche clearing to keep a number of the new model candidates in each of niches from exceeding a maximum number. The dividing, generating and deriving operations are then iterated. Model caching may be performed by restricting the crossover to the model term level or above.

For calibration (24) for quantitative SPECT, a multiple energy emission source (11) is used for calibration. The planar sensitivities and/or uniformities are determined at different emission energies based on detections from the multiple energy emission source. For estimating (32) the activity concentration, sensitivities and/or uniformities based on measures (26) at different emission energies increase accuracy. The multiple energy emission source (11) may alternatively or additionally be used to calibrate (40) a dose calibrator (15).

For calibration (24) for quantitative SPECT, a multiple energy emission source (11) is used for calibration. The planar sensitivities and/or uniformities are determined at different emission energies based on detections from the multiple energy emission source. For estimating (32) the activity concentration, sensitivities and/or uniformities based on measures (26) at different emission energies increase accuracy. The multiple energy emission source (11) may alternatively or additionally be used to calibrate (40) a dose calibrator (15).

A representative positron emission tomography (PET) system includes a positron emission tomography detector having one or more silicon photomultipliers that output silicon photomultipliers signals. The PET system further includes a calibration system that is electrically coupled to the silicon photomultipliers. The calibration system determines a single photoelectron response of the silicon photomultipliers signals and adjusts a gain of the silicon photomultipliers based on the single photoelectron response.

A method for preparing a deck for a process is disclosed. The deck can be prepared with any necessary components, and then an imaging device can capture an image of the deck. This image can be compared with a reference image and any differences identified. The differences can be indicated in the image and shown to an operator, such that the operator can correct any errors associated with the differences.