Description
HARP™ PMMA (polymethyl methacrylate) is engineered for high-resolution direct-write e-beam lithography. The 1,000,000 MW formulation provides excellent image contrast and feature fidelity while maintaining strong adhesion to silicon, III-V, and common dielectric/metal stacks. Manufactured in anisole and compatible with MIBK/IPA developers, HARP PMMA integrates easily into standard PMMA process flows. In a bilayer with HARP-C™ copolymer, it yields controlled undercut ideal for T-gate fabrication. Beyond patterning, HARP PMMA serves as a reliable protective or sacrificial coating for wafer thinning and release processes, and is also suited to X-ray LIGA workflows. Competes directly with 950 PMMA while offering best-in-class resolution at the highest molecular weight.
Key features
- Tone: Positive
- Exposure: Direct-write e-beam (also suited for X-ray LIGA)
- Film thickness: 0.07 - 3.75 µm
- Developer: MIBK/IPA
- Solvent system: Manufactured in anisole; HARP™ PMMA products available in safe solvents (anisole, ethyl lactate)
- Adhesion: Excellent to a wide range of substrates; suitable as protective/sacrificial layers
- Bilayer compatibility: Pair with HARP-C™ copolymer for undercut profiles in T-gate structures
- Drop-in Replacement for: 950 PMMA
| Current Resist | KemLab Replacement | Approx. KemLab FT (microns) Range |
| 950 PMMA A2 | 1000 HARP eB 0.1 | 0.07 – 0.10 |
| 950 PMMA A3 | 1000 HARP eB 0.2 | 0.10 – 0.25 |
| 950 PMMA A4 | 1000 HARP eB 0.3 | 0.20 – 0.44 |
| 950 PMMA A5 | 1000 HARP eB 0.4 | 0.35 – 0.65 |
| 950 PMMA A6 | 1000 HARP eB 0.7 | 0.50 – 1.00 |
| 950 PMMA A8 | 1000 HARP eB 1.3 | 1.00 – 1.80 |
| 950 PMMA A9 | 1000 HARP eB 1.7 | 1.50 – 2.50 |
| 950 PMMA A11 | 1000 HARP eB 2.7 | 2.00 – 3.75 |
