The manufacturing process applied to quartz crystal frequency control components is severely constrained by defects present in the cultured quartz materials. Attempts by crystal component makers to adapt low cost, high quality batch photolithographic processing techniques pioneered by the semiconductor industry are blocked by the inability of current quartz to withstand strong etchants. The quartz wafers develop etch pipes or holes which seriously reduce yields. Etch pipes appear to result from bundles of crystal dislocations decorated with impurities. The role of inclusions on creating dislocations in single crystal cultured quartz is investigated. Material is characterized using X-ray topography, and ammonium bifluoride etchants to highlight bundled, decorated dislocations prone to etch pipe formation. Growth Chamber wall conditions, an important factor in creating solid inclusions are varied by utilizing mechanical and chemical cleaning procedures. Additionally, raw materials and process solutions are purified. The feasibility of improving dislocation densities in crystals is studied.The potential commercial application as described by the awardee: The creation of etch pipe free cultured quartz would enable U.S. quartz crystal component manufacturers to adapt low cost, high quality batch photolithographic techniques used in the semiconductor industry to the production of quartz components. Additionally, innovative crystal shapes and orientation could be introduced to improve the performance of the components.
