Potassium Hydroxide Silicon Anisotropic Etch (KOH)
CAS Number: 1310-58-3
Potassium hydroxide (KOH) aqueous solution is the classical anisotropic silicon etchant used in MEMS fabrication, offering extremely high selectivity between crystallographic planes. Typical concentrations of 20–40 wt% at 70–80°C provide well-controlled etch rates with excellent {100}/{111} selectivity exceeding 100:1. KOH is the preferred etchant for non-CMOS MEMS devices where alkali metal contamination is acceptable.
Technical Specifications
| appearance | Colorless clear liquid |
| purity (%) | ≥99.5 (KOH assay, dry basis) |
| heavy metals | ≤5 ppm each |
| concentration (wt%) | 20–45% (customizable) |
| Si etch rate (80°C, 30% KOH) | ≈ 1.0–1.5 µm/min |
Applications
- MEMS bulk silicon anisotropic micromachining
- V-groove waveguide and fiber-optic alignment structure
- Pressure sensor diaphragm etching
- Microfluidic channel fabrication
- Accelerometer and gyroscope proof mass definition
Key Features
- Outstanding {100}/{111} selectivity (>100:1) for precise microstructure fabrication
- Well-documented etch rate vs. temperature/concentration data available
- SiO2 and Si3N4 serve as excellent etch masks with high selectivity
- Cost-effective alternative to TMAH for non-CMOS MEMS applications
Send Inquiry
CAS Number
1310-58-3
Category
Semiconductor Etching ChemicalsAvailability
In StockSample
Dispatched within 5 days
More in Semiconductor Etching Chemicals
Acetone Semiconductor Grade (Photoresist Removal)
67-64-1
Aluminum Chloride ALD Precursor (AlCl3)
7446-70-0
Ammonia Semiconductor Grade (NH3 Nitride CVD)
7664-41-7
Ammonium Fluoride Semiconductor Grade (NH4F 40%)
12125-01-8
Ammonium Hydroxide Semiconductor Grade (NH4OH SC-1)
1336-21-6
Argon Sputtering Gas (Ar Ultra-Pure)
7440-37-1
Bottom Anti-Reflective Coating (BARC)
Buffered Oxide Etch (BOE) NH4F/HF
7664-39-3