Femtosecond laser direct hard mask writing for selective facile micron-scale inverted-pyramid patterning of silicon
Bibliographic record
Abstract
We report on the fabrication of high-fidelity inverted-pyramids in crystalline silicon (c-Si) at the 1 μm scale through the selective removal of a silicon nitride (SiNx) hard-mask with a 522 nm femtosecond (fs) laser and subsequent alkaline potassium hydroxide (KOH) etching. Through a series of systematic experiments on a range of hard-mask thicknesses, the use of 20 nm thick SiNx film yielded a 0.6 μm diameter laser-ejected aperture in the hard-mask at a single pulse fluence of 0.45 J cm−2, resulting in 1 μm wide inverted-pyramid structure in c-Si after KOH etching. Anisotropic KOH etching of the partially amorphized c-Si underlying the fs-laser patterned hard mask was found to render clean (111) planes of c-Si. An array of inverted-pyramids on c-Si surfaces as large as 4 cm2 was produced with a defect density of less than 1 in 104. This facile, non-contact, and cleanroom-independent technique serves a variety of applications including anti-reflective texturing of thin c-Si for photovoltaics, wafer marking, labeling, and fabrication of microfluidic and optical devices or laboratories on silicon wafers.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 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) | 0.001 | 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 source (direct Gemma or distilled Codex), 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".