Abstract: In accordance with various embodiments of the disclosed subject matter, a phototransistor comprises an NPN or PNP phototransistor having a base including a Si-region, a Ge-region, and a Ge—Si interface region wherein photons are absorbed in the Ge region and conduction-band electrons are attracted to the interface region such that the electrons' mobility is enhanced thereby.

Abstract: In accordance with various embodiments of the disclosed subject matter, a phototransistor comprises an NPN or PNP phototransistor having a base including a Si-region, a Ge-region, and a Ge-Si interface region wherein photons are absorbed in the Ge region and conduction-band electrons are attracted to the interface region such that the electrons' mobility is enhanced thereby.

Abstract: A number of micromachined devices including a micromachined pump for on-chip vacuum is provided. For example, a single-chip micromachined implementation of a Knudsen pump having one or more stages and which uses the principle of thermal transpiration with no moving parts is provided. A six-mask microfabrication process to fabricate the pump using a glass substrate and silicon wafer is shown. The Knudsen pump and two integrated pressure sensors occupy an area of 1.5 mm×2 mm. Measurements show that while operating in standard laboratory conditions, this device can evacuate a cavity to 0.46 atm using 80 mW input power. High thermal isolation is obtained between a polysilicon heater of the pump and the rest of the device.

Abstract: A relatively simple and inexpensive micromachined arrayed thermal probe apparatus, system for thermal scanning a sample in a contact mode and cantilevered reference probe for use therein can be used for a variety of microscopy and microcalorimetry applications ranging from the monitoring of processes in semiconductor manufacturing to the characterization of nano-scale materials, imaging of biological cells, and even data storage. Probes are designed to have very high thermal isolation and high mechanical compliance, providing advantages in both performance and ease of operation. In particular, an array of probes can be used for high throughput contact mode scanning of soft samples without mechanical feedback, and can, therefore, be used in wide arrays for high-speed measurements over large sample surfaces. The probes are preferably manufactured by a photolithographic fabrication process, which permits large numbers of probes to be made in a uniform and reproducible manner at low cost.

Abstract: A relatively simple and inexpensive micromachined arrayed thermal probe apparatus, system for thermal scanning a sample in a contact mode and cantilevered reference probe for use therein can be used for a variety of microscopy and microcalorimetry applications ranging from the monitoring of processes in semiconductor manufacturing to the characterization of nano-scale materials, imaging of biological cells, and even data storage. Probes are designed to have very high thermal isolation and high mechanical compliance, providing advantages in both performance and ease of operation. In particular, an array of probes can be used for high throughput contact mode scanning of soft samples without mechanical feedback, and can, therefore, be used in wide arrays for high-speed measurements over large sample surfaces. The probes are preferably manufactured by a photolithographic fabrication process, which permits large numbers of probes to be made in a uniform and reproducible manner at low cost.

Abstract: A number of micromachined devices including a micromachined pump for on-chip vacuum is provided. For example, a single-chip micromachined implementation of a Knudsen pump having one or more stages and which uses the principle of thermal transpiration with no moving parts is provided. A six-mask microfabrication process to fabricate the pump using a glass substrate and silicon wafer is shown. The Knudsen pump and two integrated pressure sensors occupy an area of 1.5 mm×2 mm. Measurements show that while operating in standard laboratory conditions, this device can evacuate a cavity to 0.46 atm using 80 mW input power. High thermal isolation is obtained between a polysilicon heater of the pump and the rest of the device.

Abstract: A micromachined shock sensor has a substrate with a surface on which are formed an array of acceleration sensing units. Each sensing unit has a mount fixed to the substrate, a cantilever beam extending from the mount, and a proof mass fixed to the cantilever beam and supported above the substrate to permit translation of the proof mass and bending of the cantilever beam in a plane parallel to the substrate surface. Sensing electrodes are formed on the substrate on opposite sides of the proof mass such that displacement of the proof mass in response to acceleration brings the proof mass into contact with one or the other of the electrodes at a sufficient acceleration level, effectively closing a switch and providing an electrical output signal that can be detected. The multiple acceleration sensing units are formed to make contact at different levels of acceleration, allowing the shock sensor to allow measurements over a range of accelerations.

Abstract: A micromachined shock sensor has a substrate with a surface on which are formed an array of acceleration sensing units. Each sensing unit has a mount fixed to the substrate, a cantilever beam extending from the mount, and a proof mass fixed to the cantilever beam and supported above the substrate to permit translation of the proof mass and bending of the cantilever beam in a plane parallel to the substrate surface. Sensing electrodes are formed on the substrate on opposite sides of the proof mass such that displacement of the proof mass in response to acceleration brings the proof mass into contact with one or the other of the electrodes at a sufficient acceleration level, effectively closing a switch and providing an electrical output signal that can be detected. The multiple acceleration sensing units are formed to make contact at different levels of acceleration, allowing the shock sensor to allow measurements over a range of accelerations.

Abstract: Photodiode arrays are formed with close diode-to-diode spacing and minimized cross-talk between diodes in the array by isolating the diodes from one another with trenches that are formed between the photodiodes in the array. The photodiodes are formed of spaced regions in a base layer, each spaced region having an impurity type opposite to that of the base layer to define a p-n junction between the spaced regions and the base layer. The base layer meets a substrate at a boundary, with the substrate being much more heavily doped than the base layer with the same impurity type. The trenches extend through the base layer and preferably into the substrate. Minority carriers generated by absorption of light photons in the base layer can only migrate to an adjacent photodiode through the substrate. The lifetime and the corresponding diffusion length of the minority carriers in the substrate is very short so that all minority carriers recombine in the substrate before reaching an adjacent photodiode.