| dc.description.abstract | The Bosch process is a type of deep reactive-ion etching (DRIE) of silicon. It is a type of plasma etching, or dry etching, that uses physical and chemical processes to etch the surface of a silicon sample. Due to its highly desirable results, this process is used in several applications, such as nanoscale MOSEFTS, microelectromechanical systems, and micro-optics. This process is unique because it switches between process gases or plasma chemistries to create a fluorine base for etching while also creating a carbon layer for sidewall protection. The process cycles between etching with fluorine and depositing a carbon layer coating, which is a process known as passivation. During standard reactive-ion etching (RIE), there is possibility of rough sidewalls, a low aspect ratio, and growth of silicon grass at the bottom of the feature trench, some of which can be as tall as the etched feature itself. Thus, the Bosch process is a highly effective process that results in higher etch rates than regular RIE. In addition, it enables selectivity and anisotropy and eliminates the possibility of silicon grass formation in etched trenches. The most desirable aspects of this process are its abilities to etch while maintaining smooth sidewalls and produce high-aspect-ratio features with vertical sidewalls. The Bosch process for DRIE will be implemented on an Oxford Plasmalab100 ICP RIE machine. Throughout development, thin film deposition, thermal oxidation, photolithography, silicon dicing, wet etching, and cross-sectional scanning electron microscopy processes will be used. | |
