Choline Hydroxide

• Organic base
• High purity, low trace metal
• Available at 45 wt%
• Water or solvent based
• TMAH replacement
• Developer, stripper, and PERR
• Etching agent
• CMP slurries and pCMP Cleans

* Thickness measured with Napson Cresbox 4 point-probe tester and Filmetrics.

• Choline Hydroxide, XHE-125, and XHE-128 have comparable developing rates relative to 2.38 wt% TMAH for positive PR
• Developing rates can be optimized across a broad working window
• Developing rates are linear with concentration, above a minimum concentration

• Choline Hydroxide demonstrated good performance for negative PR
• XHE-125 has similar performance, increasing the concentration to 5 wt% to match 2.38 wt% TMAH
•  Developing rates have a linear relationship with concentration, even at low concentrations

• Cu wafer treated with E-GRADE® THEMAH and E-GRADE® CHOLINE HYDROXIDE demonstrated smoother surfaces comparing to Cu treated with TMAH.

• Silicon wafers, etched with E-GRADE® Choline Hydroxide, demonstrate significant reductions in reflectivity and improvement in uniformity when compared to wafers treated with TMAH. This texturization reduces light reflection and improves absorption for photovoltaic devices.

• Positive tone Novolak photoresist is well developed at room temperature with E-GRADE® Choline Hydroxide.

• Concentration dependence of pH values for TMAH and Choline in water.

• At proper pH and concentration, E-GRADE® Choline Hydroxide with H₂O₂ can be used for TiN etch (etch rate > 20 nm/min). The degradation rate of H₂O₂ with Choline Hydroxide was observed to be much slower than with TMAH. Degradation rate is based on 24 hr average at 45°C.