Photolithography and etch processes are foundational to semiconductor device manufacturing. Together, they are used to form the patterns that make the circuitry on semiconductor wafers.
In photolithography, the wafer is cleaned, and then a barrier layer is formed, followed by photoresist application, soft baking, mask alignment, exposure and development, and then hard baking. Si nitride films are often used to form the barrier layer and/or as the mask materials, because they form a barrier against both water and sodium and have a slower etch rate than the exposed Si to be removed.
Next, either wet or dry etch steps are used to remove silicon from the exposed areas of the wafer not protected by the photoresist. While dry etch processes are used for the finer patterning steps of today’s advanced node devices, wet etch processes are used to remove materials from larger areas of the wafer.
Before further processing steps can take place, resist stripping and Si nitride etch is done to remove any traces of the materials. This is critical to prevent device damage due to defects caused by resist and Si nitride film residues. This process is done in a wet bath, using a combination of chemistries and di-ionized water, heated to high temperatures.
The experts at Kinetics developed MEGATHERM™ High Temperature Quartz Baths to stand up to the rigors of resist stripping and silicon nitride etch. The product line was designed especially for a low contamination and particle-free environment.