Effects of mask material conductivity on lateral undercut etching in silicon nano-pillar fabrication
Bibliographic record
Abstract
High aspect ratio silicon structures have gained significant interest due to their vast applications. Minimal lateral etch under the mask is essential to achieve such high aspect ratio structures. Previously, the authors reported that chromium oxide is better than metallic chromium as a hard mask for silicon etching in terms of etch rate and selectivity to resist during mask structure fabrication. Here, it is reported that a metal oxide etch mask also gives less lateral etch than a metal etch mask. Following mask structure fabrication by electron beam lithography and lift-off, silicon was etched using a nonswitching (i.e., SF6 and C4F8 gases simultaneously injected into a chamber) pseudo-Bosch process. The amount of lateral etching right underneath the mask is less (roughly half) for Cr2O3 and Al2O3 masks than Cr or Al masks. One plausible explanation for the difference is the metal-assisted plasma etching effect where the metal catalyzes the chemical reaction by injecting holes into the silicon in contact. It is also reported that a higher bias power leads to less undercut than a lower one, due to increased and more directional physical bombardment by ions.
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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 | 0.001 | 0.001 |
| 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".