Abstract: A method for epitaxial growth of silicon carbide using chemical vapor deposition (CVD) is provided. This method utilizes halogenated carbon precursors and control of the gas-phase interaction of halogen-containing intermediate chemical products involving silicon and carbon, which ensures quality and homogeneity across the silicon carbide crystals. It also ensures a possibility to achieve device-quality epitaxial layers at lower growth temperatures as well as on on-axis or low off-angle substrate surfaces. The growth method can be applied to forming SiC device regions of desirable shape and dimensions by restricting the growth into windows formed in non-silicon carbide region on the top of SiC substrate. Application of the methods described herein will greatly benefit the production of high quality silicon carbide materials and devices.

Abstract: The invention provides a method of design for a time-of-flight mass spectrometer that is compact and has high mass resolution over a broad range of ion masses. This method of design, for the high-resolution analysis of analyte ions in the time-of-flight mass spectrometer, includes decreasing the strength of the time-dependent extraction potential according to a predetermined continuous function so as to spread out the energy distribution of the ions and achieving high mass resolution over a broad range of masses without altering the time dependence or magnitude of the applied potentials, across the acceleration region and ion mirror, and the time-dependent extraction potential, and not changing the physical dimensions of the mass spectrometer. Using this method of design, mass resolution of approximately or greater than 10,000 can be achieved over approximately five orders of magnitude of mass for a time-of-flight mass spectrometer having a total overall length of less than 46 cm.