Z L Zhang

Bio: Z L Zhang is an academic researcher from Cornell University. The author has contributed to research in topics: Etching (microfabrication) & Reactive-ion etching. The author has an hindex of 1, co-authored 1 publications receiving 105 citations.

A RIE process for submicron, silicon electromechanical structures

Abstract: A reactive ion etching (RIE) process is used for the fabrication of submicron, movable single-crystal silicon (SCS) mechanical structures and capacitor actuators. The process is called SCREAM for single crystal reactive etching and metallization process. The RIE process gives excellent control of lateral dimensions (0.2 mu m approximately 2 mu m) while maintaining a large vertical depth (1 mu m approximately 4 mu m) for the formation of high aspect ratio, freely suspended SCS structures. The silicon etch processes are independent of crystal orientation and produce controllable vertical profiles. The process also incorporates process steps to form vertical, 4 mu m deep, aluminum, capacitor actuators. Using SCREAM, the authors have designed, fabricated and tested two-dimensional x-y microstages and circular SCS structures. For the x-y stage they measured a maximum displacement of +or-6 mu m in x and y with 40 V DC applied to either x or y, or both x and y actuators. The process technology offers the capability to use a structural stiffness as low as 10-2 N m-1.

Bulk micromachining of silicon

Abstract: Bulk silicon etching techniques, used to selectively remove silicon from substrates, have been broadly applied in the fabrication of micromachined sensors, actuators, and structures. Despite the more recent emergence of higher resolution, surface-micromachining approaches, the majority of currently shipping silicon sensors are made using bulk etching. Particularly in light of newly introduced dry etching methods compatible with complementary metal-oxide-semiconductors, it is unlikely that bulk micromachining will decrease in popularity in the near future. The available etching methods fall into three categories in terms of the state of the etchant: wet, vapor, and plasma. For each category, the available processes are reviewed and compared in terms of etch results, cost, complexity, process compatibility, and a number of other factors. In addition, several example micromachined structures are presented.

Lab-on-chip technologies: making a microfluidic network and coupling it into a complete microsystem : a review

Abstract: Microfluidics is an emerging field that has given rise to a large number of scientific and technological developments over the last few years. This review reports on the use of various materials, such as silicon, glass and polymers, and their related technologies for the manufacturing of simple microchannels and complex systems. It also presents the main application fields concerned with the different technologies and the most significant results reported by academic and industrial teams. Finally, it demonstrates the advantage of developing approaches for associating polymer technologies for manufacturing of fluidic elements with integration of active or sensitive elements, particularly silicon devices.

SCREAM I: A single mask, single-crystal silicon, reactive ion etching process for microelectromechanical structures

Abstract: A single-crystal slhcon, high aspect ratlo, low-temperature process sequence for the fabrlcatlon of suspended rmcroelectromechamcal structures (MEMS) usmg a smgle hthography step and reactwe Ion etching (RIE) IS presented The process IS called SCRJZAM I (single-crystal reactwe etchmg and metalhzatmn) SCREAM I IS a bulk mlcromachmmg process that uses RIE of a s~hcon substrate to fabricate suspended movable smgle-crystal s&on (SCS) beam structures Beam elements wth aspect ratios of 10 to 1 and widths rangmg from 0 5 to 4 0 Frn have been fabricated All process steps are low temperature (<3OO “C), and only conventronal sd~con fabrlcation tools are used photohthography, RIE, MIE, plasma-enhanced chemxal-vapor deposrtlon (PECVD) and sputter deposlhon SCREAM I IS a self-ahgned process and uses a smgle lithography step to define beams and structures srmultaneously as well as all necessary contact pads, electrIcal mterconnects and lateral capaators SCREAM I has been specifically deslgned for integration with standard Integrated cmxnt (IC) processes, so MEM deuces can be fabricated adjacent to prefabricated analog and dIgItal carcuitry In this paper we present process parameters for the fabncatlon of discrete SCREAM I devices We also discuss mask design rules and show micrographs of fabncated deuces

Capacitance Based Tunable Micromechanical Resonators

Abstract: We present actuators which tune the resonant frequency of micromechanical oscillators. Experimental results show resonant oscillations from 7.7% to 146% of the original resonant frequency. Numerical results substantiate these results. Two failure modes have been identified which limit

Apparatus and method for the generation, separation, detection, and recognition of biopolymer fragments

Abstract: This invention is an integrated instrument for the high-capacity electrophoretic analysis of biopolymer samples. It comprises a specialized high-voltage, electrophoretic module in which the migration lanes are formed between a bottom plate and a plurality of etched grooves in a top plate, the module permitting concurrent separation of 80 or more separate samples. In thermal contact with the bottom plate is a thermal control module incorporating a plurality of Peltier heat transfer devices for the control of temperature and gradients in the electrophoretic medium. Fragments are detected by a transmission imaging spectrograph which simultaneously spatially focuses and spectrally resolves the detection region of all the migration lanes. The spectrograph comprises a transmission dispersion element and a CCD array to detect signals. Signal analysis comprises the steps of noise filtering, comparison in a configuration space with signal prototypes, and selection of the best prototype. Optionally post-processing is done by a Monte-Carlo simulated annealing algorithm to improve results. Optionally, an array of micro-reactors can be integrated into the instrument for the generation of sequencing reaction fragments directly from crude DNA samples.