Selecting Equipment for the KOH Wafer Etching Process

KOH (potassium hydroxide) etching has become increasingly important as a solution in creating microscopic structures in silicon. The wafer etching process using KOH etching is relatively safe and can be monitored by regulating the bath temperature and doping of the silicon.

The silicon wafer (which is masked with a material that's impenetrable by KOH, most often silicon dioxide or silicon nitride) is immersed in the KOH solution. In order to reach a desired etch rate, the temperature must be controlled. KOH etching is extremely sensitive to temperature variations at temperatures at 60 degrees centigrade and above, that's why accurate control of the temperature is a key factor to produce accurate etching results.

Aside from the variations of temperature, the orientation of the crystal planes in the silicon and the doping of the silicon with boron can also significantly affect the rate and the direction of the etch.

Selecting the right KOH equipment will lead to delivering precise etching results you expected. Modutek supports KOH etching as one of the wafer etching process options within their wet bench process stations.  

Modutek's equipment includes the TFa and TT series Teflon heated tanks which are ideal for supporting KOH etching requirements. The tanks are available in standard size (for single or double capacity) or customized sizes.

The TFa series high-temperature overflow tanks and the TT series static tanks are both PFA Teflon tanks with a Teflon-covered liquid path. It also includes the 360-degree overflow filtration through serration overflow, a condensing Teflon refluxor with Teflon cooling units (optional), an aspirator valve system, a pneumatically actuated auto cover, as well as a Teflon gravity drain.

Learn more about “Selecting Equipment for KOH Wafer Etching Process” by reading the main blog article. You contact Modutek at 866-803-1533 for a free consultation or quote, or send an email to modutek@modutek.com.