Massachusetts Institute of Technology

Richard J Molnar

Jeehwan Kim

Dirk Robert Englund

Michael W Geis

Mark Alexander Hollis

Antonio Sanchez-Rubio

Robert K Reich

Thomas H Jeys

Richard M Osgood, Iii

David L Spears

Jinendra K Ranka

Travis Wade

A buffer layer is employed to fabricate diamond membranes and allow reuse of diamond substrates. In this approach, diamond membranes are fabricated on the buffer layer, which in turn is disposed on a diamond substrate that is lattice-matched to the diamond membrane. The weak bonding between the buffer layer and the diamond substrate allows ready release of the fabricated diamond membrane. The released diamond membrane is transferred to another substrate to fabricate diamond devices, while the diamond substrate is reused for another fabrication.

Systems and methods for fabricating single-crystalline diamond membranes

Herein is provided a growth structure for forming a free-standing layer of crystalline material having at least one crystallographic symmetry. The growth structure includes a host substrate and a separation layer disposed on the host substrate for growth of a layer of the crystalline material thereon. The separation layer has a separation layer thickness, and is mechanically weaker than the host substrate and the crystalline material. An array of apertures is in the separation layer, each aperture extending through the separation layer thickness.

Production of free-standing crystalline material layers

A particle detection system that images and detects particles in a fluid flow stream through use of detector array(s) is described. The detection system may include light source arrays that may selectively illuminate a particle in a fluid stream. The detection system may also include a detector array employing smart binning to read the measured signals. The smart binning of the detector array may be achieved through knowledge of an exact particle location provided by a position sensitive detector. The detector array(s) may be low cost based on intelligence built into the system. This particle detection system may be particularly useful for detection and discrimination of different particle types since the read-out of the particle signals can be accomplished with low noise and can be flexible enough to optimize the read out measurements for each particle. The particle detection system may be used, for example, in early warning contamination detection systems and manufacturing processes.

Method and apparatus for detecting and discriminating particles in a fluid

Provided is a method for producing a nitride layer on a growth substrate. First a pretreatment layer is formed on the growth substrate, and then the formed pretreatment layer is exposed to a gaseous environment that is thermochemically reactive with the pretreatment layer. After gaseous environment exposure of the pretreatment layer, there is carried out an epitaxial growing process to produce on the substrate a nitride layer material defined as In.sub.x Ga.sub.y Al.sub.1-x-y N, where 0.ltoreq.x.ltoreq.1; 0.ltoreq.y.ltoreq.1; and 0.ltoreq.x+y.ltoreq.1. For example, a pretreatment layer of ZnO can be deposited on a sapphire growth substrate and then subjected to a gaseous environment, e.g., including HCl- and/or NH.sub.3 -containing gas, that is thermochemically reactive with the ZnO. Then an epitaxial layer of GaN can be grown by a hydride vapor phase epitaxial process on the pretreated substrate. The growth substrate can include a plane of mechanical weakness that is parallel with a predominant nitride growth surface of the substrate, and that is either inherently exhibited by the substrate or that is produced by processing of the substrate. Similarly, an interlayer of material characterized by a plane of mechanical weakness parallel with the predominant nitride growth surface can be formed on the substrate, preferably after the pretreatment layer deposition and gaseous environment exposure steps.

Process for producing high-quality III-V nitride substrates

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Harvard, MA, United States of America

Richard J Molnar