Van der Waals epitaxy of nearly single-crystalline nitride films on amorphous graphene-glass wafer

Van der Waals epitaxy provides a fertile playground for the monolithic integration of various materials for advanced electronics and optoelectronics. Here, a previously unidentified nanorod-assisted van der Waals epitaxy is developed and nearly single-crystalline GaN films are first grown on amorphous silica glass substrates using a graphene interfacial layer. The epitaxial GaN-based light-emitting diode structures, with a record internal quantum efficiency, can be readily lifted off, becoming large-size flexible devices. Without the effects of the potential field from a single-crystalline substrate, we expect this approach to be equally applicable for high-quality growth of nitrides on arbitrary substrates. Our work provides a revolutionary technology for the growth of high-quality semiconductors, thus enabling the hetero-integration of highly mismatched material systems.

High-Consistency Optical Fiber Fabry–Perot Pressure Sensor Based on Silicon MEMS Technology for High Temperature Environment

This paper proposes a high-temperature optical fiber Fabry–Perot pressure sensor based on the micro-electro-mechanical system (MEMS). The sensing structure of the sensor is composed of Pyrex glass wafer and silicon wafer manufactured by mass micromachining through anodic bonding process. The separated sensing head and the gold-plated fiber are welded together by a carbon dioxide laser to form a fiber-optic Fabry–Perot high temperature pressure sensor, which uses a four-layer bonding technology to improve the sealing performance of the Fabry–Perot cavity. The test system of high temperature pressure sensor is set up, and the experimental data obtained are calculated and analyzed. The experimental results showed that the maximum linearity of the optical fiber pressure sensor was 1% in the temperature range of 20–400 °C. The pressure sensor exhibited a high linear sensitivity of about 1.38 nm/KPa at room temperature at a range of pressures from approximarely 0-to 1 MPa. The structure of the sensor is characterized by high consistency, which makes the structure more compact and the manufacturing process more controllable.

Improved Die Attribute Recognition via Colored Glass Wafer

The rise of various Wafer technologies has been developed based on industries and applications requirement. Highest quality of material characterization is complex and requires specialized process equipment and manufacturing procedures to meet defined design standards. The paper presents distinctive glass wafer-level fabrication technology that will enhance its properties with respect to pattern recognition system (PRS) at back-end manufacturing for industrial applications. Feasibility of colored glass wafer has been built into proposed conception to manufacture wafer-level packaging. The idea from transparent to colored glass wafer came from manufacturing key challenges that cutting sequence during pattern recognition cannot be distinguished. The proposed solution will mitigate high risk of misaligned cut at wafer sawing and its potential attachment on leadframe during die attach. glass wafer dice, transparent in nature, intermittently encountered multiple PRS assist during Wafer sawing and die attach as it hardly recognizes its cutting positions. Since dependent of machine capability limitations, misaligned cut is inevitable and usually happen occasionally. Addressing its unrecognizable characteristic, proposed colored glass wafer and with visible outline and saw lane fabrication was conceptualized instead of seeking ideal and high equipment model that can differentiate its opaque feature. The colored glass wafer and with visible outline and saw lane naturally creates segmentation visibly and will not be parameter dependent during manufacturing.

Toward on-board microchip synthesis of CdSe vs. PbSe nanocrystalline quantum dots as a spectral decoy for protecting space assets

Fabrication of the reaction chamber using silicon carbide. (A) A schematic sketch of the fabrication flow; (B) a photograph of a transparent 6 inch SiC-on-glass wafer; (C) the surface morphology of the SiC film.

Monolithically Integrated Diffused Silicon Two-Zone Heaters for Silicon-Pyrex Glass Microreactors for Production of Nanoparticles: Heat Exchange Aspects

We present the design, simulation, fabrication and characterization of monolithically integrated high resistivity p-type boron-diffused silicon two-zone heaters in a model high temperature microreactor intended for nanoparticle fabrication. We used a finite element method for simulations of the heaters’ operation and performance. Our experimental model reactor structure consisted of a silicon wafer anodically bonded to a Pyrex glass wafer with an isotropically etched serpentine microchannels network. We fabricated two separate spiral heaters with different temperatures, mutually thermally isolated by barrier apertures etched throughout the silicon wafer. The heaters were characterized by electric measurements and by infrared thermal vision. The obtained results show that our proposed procedure for the heater fabrication is robust, stable and controllable, with a decreased sensitivity to random variations of fabrication process parameters. Compared to metallic or polysilicon heaters typically integrated into microreactors, our approach offers improved control over heater characteristics through adjustment of the Boron doping level and profile. Our microreactor is intended to produce titanium dioxide nanoparticles, but it could be also used to fabricate nanoparticles in different materials as well, with various parameters and geometries. Our method can be generally applied to other high-temperature microsystems.