Construction of quartz crystal etching rate database based on Hubbard interpolation method

This study utilizes the Hubbard interpolation method to partition the etching directions of quartz crystal into 96 triangular regions based on 13 crystal planes. The etching rates in various directions on each crystal plane of quartz can be obtained through mask design and rate measurement experiment. By measuring the etching rates of multiple types of crystal-cut wafers and considering the symmetry of quartz, the etching rates in various directions on the 13 crystal planes can be determined. At the boundaries of the triangular regions, a series of sampling points are selected to further subdivide the triangular regions into smaller triangles. Utilizing the Hubbard interpolation method, the etching rates of crystal orientations within each small region can be computed. Finally, employing Hubbard interpolation on each triangular region yields the complete quartz crystal etching rate database covering all directions.