X-ray topography used as a routine tool in the evaluation of the crystal quality of GaAs substrate wafers
Bibliographic record
Abstract
Asymmetric crystal x-ray topography (ACT) which can image entire 3" wafers on radiography film using a Cu x-ray source in less than 30 min. is a fast, convenient tool for routine wafer prescreening. An ACT study of over 70 SI LEC GaAs wafers revealed typical defects: low angle grain boundaries, dislocation cell structure, inclusions, precipitates, and included mosaic structure. A comparison of wafers from ten different vendors showed that the concentration of defects can vary significantly. Two correlations were found between crystal quality and wafer manufacturability. First, wafers from boules which had a high density of clustered low angle grain boundaries were found to be too mechanically fragile to survive all the processing steps required in device fabrication. Second, wafers from boules which showed the presence of large included mosaic crystals all showed poor or erratic cleaving characteristics causing the loss of many devices.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".