Laser RIE Process for Etching of Organic Materials
Original Publication Date: 1984-Jun-01
Included in the Prior Art Database: 2005-Feb-04
Reactive ion etching (RIE) can be used to remove organic materials, such as polyimide and photoresist. In this process, a plasma discharge is induced in a low pressure gas to produce highly reactive species, which then etch the organic material. An example is a mixture of CF4 and oxygen, which is used to etch polyimide. In order to replace the expensive plasma etching systems used for RIE processing, a CO2 laser is used to induce a plasma discharge in a mixture of oxygen and a fluorine- or chlorine-containing gas. Gases, such as SF6, CF2Cl2, C2F6 and CF4, have vibrational modes that can be exited by 10 mm radiation. For moderate energy densities, on the order of 4 J/cm2, multiphoton dissociation leads to the production of reactive species. For instance, SF6 + nhn T SF5* + F, C2F6 + nhn T CF3* + CF3*.