How Positive Photoresists Enable Precision in Microfabrication
In the ever-evolving landscape of microfabrication, the demand for precision and miniaturisation has never been greater. From smartphones to medical implants, the intricate components that power modern technology are products of meticulous engineering at the microscopic level. At the heart of this precision lies photolithography a technique that employs light to transfer patterns onto substrates. Central to this process are photoresists, with positive photoresists playing a pivotal role in achieving the high-resolution patterns essential for today's advanced devices. Understanding Positive Photoresists Photoresists are light-sensitive materials applied to substrates, such as silicon wafers, to create patterned coatings. They are broadly categorised into positive and negative types. Positive photoresists become more soluble in a developer solution upon exposure to light, allowing the exposed regions to be washed away. This property enables the precise transfer of in...