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Sensor arrays are a key tool in the field of neuroscience for noninvasive recording of the activity of biological networks, such as dissociated neurons or neural tissue. A high-density sensor array complementary metal-oxide-semiconductor chip is presented with 16 K pixels, a frame rate of 2 kiloframes per second, and a pitch of 7.8 /spl mu/m /spl times/ 7.8 /spl mu/m for imaging of neural activity. The related circuit and system issues as well as process aspects are discussed. A mismatch-canceling calibration circuitry with current mode signal representation is used. Results from first biological experiments are presented, which prove full functionality of the chip.

A pure analytical method for extraction of the small-signal equivalent circuit parameters from measured data is presented and successfully applied to heterojunction bipolar transistors (HBT's). The T-like equivalent circuit is cut into three shells accounting for the connection, and the extrinsic and intrinsic parts of the transistor. The equivalent circuit elements are evaluated in a straightforward manner from impedance and admittance representation of the measured S-parameters. The measured data are stripped during the extraction process yielding, step by step, a full set of circuit elements without using fit methods. No additional knowledge of the transistor is needed to start the extraction process with its self-consistent iteration loop for the connection shell. The extrinsic and intrinsic equivalent circuit elements are evaluated using their bias and frequency dependencies. This method yields a deviation of less then 4% between measured and modeled S-parameters. >

A kerf and tester compatible test structure is presented which allows fast and reliable evaluation of resistance and capacitance values of DRAM memory cells. The circuit is realized in a 70nm DRAM process, consumes an area of 795mum times 76mum, and requires six interconnect pads. Using standard electrical measurement equipment, the characterization method reveals resistance and capacitance based on DC current measurements and using ab-initio analytical expressions. Measured results from different lots are shown and compared to the simulated circuit behavior

A 16×8 DNA sensor array chip with fully electronic readout is based on an extended CMOS process. Requirements concerning the integration of bio-compatible interface-, sensor- and transducer-materials into a standard-CMOS-environment and circuitry design issues are discussed.

A fully electronic medium density DNA micro array is presented using a CMOS process extended by gold electrodes. The chip provides 128 sensor sites, in-sensor site current-mode A/D conversion, peripheral circuitry including bandgap and current references, D/A-converters to provide electrode bias voltages, calibration circuitry, and a 6 pin interface for power supply and serial digital data transfer.

A CMOS sensor array for extracellular, high density imaging of electrical activity of living neural networks is presented. The chip is fabricated in an extended 0.5 /spl mu/m CMOS technology, and provides 128 /spl times/ 128 pixels with a pitch of 7.8 pm; full frame rate is 2000 frames per second. Dynamic maps from single cells and cultured networks are shown.

International audience; CMOS-based sensor array chips provide new and attractive features as compared to today's standard tools for medical, diagnostic, and biotechnical applications. Examples for molecule- and cell-based approaches and related circuit design issues are discussed.

A CMOS chip-based approach is reviewed for fully electronic DNA detection. The electrochemical sensor principle used, CMOS integration of the required transducer materials, chip architecture and circuit design issues are discussed, respectively. Electrochemical and biological results obtained on the basis of medium density microarray sensor CMOS chips with 16×8 sensor sites prove proper operation.

Publisher Summary This chapter discusses the principles and several exemplary applications of silicon-based electrical microarrays, showing the power of this emerging technology. The key feature of the fully electrical biochip technology is microarrays made in silicon technology. They carry several array positions with inter-digitated electrodes on its surface. The chips are fabricated using standard silicon manufacturing methods in industrial lines, allowing a high-volume production and minimizing the cost per chip. An example of design and layout of such a transducer interface is presented in the scheme of a low-density chip. The DNA arrays are based on the fixation of oligonucleotides on a solid support and can be made by different techniques. Density is a key element for the function and use of DNA arrays, and depending on the number of different capture sites, microarrays are classified as low-density or high-density arrays. The technical platform that offers optimal features for fully electrical DNA-microarrays, with up to 16 positions, freely designed for the particular application, is described. The ultra-microelectrode gold surface allows a coupling method with alkanethiol modified capture oligonucleotide sequences and leads to a highly specific biointerface for target recognition. The chips considered in this chapter consist of a passivated silicon substrate material and of the sensor elements at their surface. The active chips allow to amplify and process the weak sensor signals on-chip and to operate such chips with a low number of contact pads, independent of the numbers of test sites per chip. The chapter presents such active chips manufactured on the basis of a specifically extended Complementary-Metal-Oxide-Semiconductor (CMOS) process.

An overview is given of CMOS-based sensor and actuator chips for in-vitro applications in the biotechnology area. We address the challenges and the potential of the combination of solid-state circuits with the wet world of bio molecules and living cells. Basic biological operating principles, market considerations, extended CMOS processing issues, and concrete circuit examples are discussed.

An overview is given of CMOS-based sensor- and actuator chips for in-vitro applications in the biotechnology area. We address the challenges and the potential of the combination of solid-state circuits with the wet world of bio molecules and living cells. Basic biological operating principles, market considerations, extended CMOS processing issues and concrete circuit examples are discussed.

A 16 /spl times/ 8 sensor array chip for fully electronic DNA detection is presented. The sensor principle is based on an electrochemical redox cycling process. The chip is fabricated on the basis of an extended 0.5 /spl mu/m CMOS process. Each sensor site of the array chip contains a complete A/D converter with a dynamic range of five decades. The 3/spl sigma/-homogeneity of the electrical response of the sensor array is better than 6% (10/sup -11/ A to 10/sup -7/ A) and better than 20% (10/sup -12/ A to 10/sup -7/ A). Proper operation of the chip is demonstrated with electrochemical and biological experiments.

Sensor arrays for fully electronic DNA detection based on an extended CMOS process are discussed. An introduction to the used DNA detection method and to the modified CMOS process is given, and special emphasis is put on design issues of circuit blocks whose function is particularly related to the electrochemical operation principle of the chip. Stability and accuracy aspects are considered in detail. Measured data are shown from electrical characterizations as well as from biological experiments.

A design strategy is presented for potentiostat circuits suitable for electronic bio sensors on CMOS. Guidelines are given to guarantee stable operation under the condition of widely varying and only roughly known electrochemical parameters. A concrete design example used in a fully electronic DNA sensor array CMOS chip is shown. Measurement results with a biological analyte applied to that chip prove proper operation of the potentiostat.

A sensor array for fully electronic detection of DNA molecules is fabricated using an extended CMOS process. A gold deposition process module and a compartment are integrated in the CMOS backend process. DNA detection is performed using a redox-cycling based electrochemical technique. Process and device issues and the impact of different processing variants on the circuit performance of the chip are discussed in detail. The result of biological experiments on chips with 128 positions are shown to prove the success of the chosen approach.

We investigate the matching behaviour of poly-silicon resistors. Experimental results from an analog CMOS process with three poly-silicon options are discussed and compared with a quantitative model which is developed using fit parameter-free analytical calculations and Monte-Carlo simulations. It is found that mismatch is directly proportional to the grain size. A relation is derived that allows us to optimize devices for low mismatch circuit applications.

A sensor for electrical detection of DNA is fabricated in a CMOS production line. A gold deposition process module is integrated in a CMOS backend process. The sensor principle is based on immobilization of singlestranded DNA probe molecules on an array consisting of interdigitated gold lines and subsequent hybridization with labeled target DNA strands. The electrical signal results from an electrochemical redox cycling process. Successful DNA detection experiments on the basis of such ‘passive’ chips are performed. This passive arrangement represents a test run for the extension of this principle to develop fully electronic DNA sensor arrays on active CMOS chips.