Karl H Schelhas

Title: Karl H. Schelhas and a Method for Manufacturing Crystal-Growth Vessels

Introduction

Karl H. Schelhas is an inventor associated with Aachen, Germany, and U.S. Philips Corporation. His work includes a patent addressing how to protect crystal-growth processes from impurities that can migrate from a vessel’s walls. The available information lists 1 patent for him.

Latest Patents

Schelhas’s listed patent, “Method of Manufacturing a Reaction Vessel for Crystal Growth Purposes,” describes applying a silicon dioxide coating to the inside of a quartz hollow member, such as a tube. The method introduces argon, gaseous silane, and a gaseous oxidant—such as dinitrogen oxide or carbon dioxide—into the heated vessel. A microwave resonator converts these gases into a porous silicon dioxide coating at a pressure of 20 to 30 mbar and a temperature of 250 to 350 degrees Celsius. The coating is then sintered, preferably to a thickness of at least 50 micrometers.

The coating is intended to prevent impurities, particularly chlorine, from diffusing through the vessel wall into its interior and disrupting crystal growth.

Career Highlights

Schelhas’s documented patent work connects materials processing with the practical requirements of crystal growth. The invention focuses on modifying the inner surface of a quartz vessel to reduce contamination during manufacturing.

Collaborations

The supplied information identifies Paul D. Kuppers and Cornelis H. Van Den Brekel as Schelhas’s coworkers. His company affiliation is U.S. Philips Corporation.

Conclusion

Karl H. Schelhas’s listed invention presents a specialized approach to improving crystal-growth vessels by using a sintered silicon dioxide coating to limit impurity diffusion.