Thin resistor film

Nonferrous alloys account for only about 2 wt % of the total chromium used ia the United States. Nonetheless, some of these appHcations are unique and constitute a vital role for chromium. Eor example, ia high temperature materials, chromium ia amounts of 15—30 wt % confers corrosion and oxidation resistance on the nickel-base and cobalt-base superaHoys used ia jet engines the familiar electrical resistance heating elements are made of Ni-Cr alloy and a variety of Ee-Ni and Ni-based alloys used ia a diverse array of appHcations, especially for nuclear reactors, depend on chromium for oxidation and corrosion resistance. Evaporated, amorphous, thin-film resistors based on Ni-Cr with A1 additions have the advantageous property of a near-2ero temperature coefficient of resistance (58). 

Modern techniques use thin-film resistors deposited directly on the area and semiconductor units are available which are considerably more sensitive than the resistive type. Dynamic measurements can also be made. The change in resistance unbalances the bridge, causing a voltage to appear across the detector terminals. This voltage is then amplified and applied to a CRO or the information can be stored digitally for future retrieval. 

Applications Although a wide range of metals can be sputtered, the method is often commercially restricted by the low rate of deposition. Applications include the coating of insulating surfaces, e.g. of crystal vibrators, to render them electrically conducting, and the manufacture of some selenium rectifiers. The micro-electronics industry now makes considerable use of sputtering in the production of thin-film resistors and capacitors . ... 

S.Q. Lud, M.G.. Nikolaides, I. Haase, M. Fischer, and A.R. Bausch, Field effect of screened charges electrical detection of peptides and proteins by a thin-film resistor. ChemPhysChem. 7, 379-384 (2006). 

M.G. Nikolaides, S. Rauschenbach, S. Luber, K. Buchholz, M. Tornow, G. Abstreiter, and A.R. Bausch, Silicon-on-insulator based thin-film resistor for chemical and biological sensor applications. ChemPhysChem. 4, 1104-1106 (2003). 

P.A. Neff, A. Naji, C. Ecker, B. Nickel, R. Klitzing, and A.R. Bausch, Electrical detection of self-assembled polyelectrolyte multilayers by a thin film resistor. Macromolecules 39, 463 466 (2006). 

Several types of palladium-based hydrogen sensors have been reported in the literature. The most notable ones are based on Pd thin-film resistors, FETs, Pd nanowires, Pd nanoparticle networks, Pd nanoclusters, and Pd nanotubes as shown in Table 15.2. 

Note that the electronic industry produces smd components called thin-film resistors of the same shape and size of Ru02 thermistors. They are usually made of a thin layer of Ni-Cr. Their resistance is extremely stable with temperature and hence they find application as inexpensive (punctual) heaters (see e.g. Chapter 11). 

Zirconium oxinitride resistors (best known are Cernox) are thin-film resistors. Typical commercial sensors have resistance values of about 105fl at IK falling to 1000 at... 

Using nitrile oxides, various compounds and materials possessing valuable properties have been prepared. Among them are thin-film resistors useful for a thermal head and comprising a nitrile oxide, ruthenium and oxygen, a method for manufacturing the resistor by coating or deposition (529), isoxazole and/or isoxazoline polyheterocyclic systems like 458, which are useful for development of a new class of ionophores (530). 

Saito S, Kuramasu K, Chiba M, Okano K, Hayashi Ch, Takahashi Ya, Nagata S. Ruthenium oxide thin-film resistor, and its manufacture, JPPat. 1990-106182 [Chem. Abstr. 1992 116 266974],... 

In addition to absolute pressure measurements, pressure sensors can be used to determine flow rates when combined with a well-defined pressure drop over a microfluidic channel. Integration of optical waveguide structures provides opportunities for monitoring of segmented gas-liquid or liquid-liquid flows in multichannel microreactors for multiphase reactions, including channels inside the device not accessible by conventional microscopy imaging (Fig. 2c) (de Mas et al. 2005). Temperature sensors are readily incorporated in the form of thin film resistors or simply by attaching thin thermocouples (Losey et al. 2001). 

A final alternative for metal patterning is the use of lasers to selectively and accurately etch small metal areas. Lasers are routinely used to trim thin-film resistors (126) they may also be used to repair defects or etch conductor lines by direct ablation in an inert atmosphere (127,129) or by laser-initiated etching in a reactive gas or liquid (128). 

Fig. 4.5 Film devices and circuits (a) thin-film resistors on glass and steatite substrates (b) thick-film resistor networks on snapstrate alumina substrate (c) various thick-film resistors (d) hybrid microcircuits. (Components kindly supplied by General Hybrid, C-MAC and...

A different analyser method based upon the same effect (deviating thermal conductivities of gaseous components) is shown in Fig. 6.127. The gas to be analysed diffuses into the measuring cell. Here, a thermal conductivity sensor made of three superimposed silicon chips shows a balanced (zero) output of two thin film resistors fitted on a membrane on the chip in the middle of this stack. One of these thin film resistors is exposed to the gas to be measured. Due to its thermal conductivity, the pair of thin film resistors show an unbalanced signal output. 

Finally, the thermal stabiUty of the specific resistance of various films is demonstrated in Fig. 18, which shows the behavior of NiWP annealed at 400 °C for 1 h, NiReP annealed at 500 °C for 1 h, and NiMoP annealed at 500 °C for 1 h. The resistance of crystalline NiMoP heat-treated at 500 °C increases with rising temperature, which indicates that the thermal stability of NiMoP with a specific resistance of 147 pQ cm is inferior to that of the other materials. While the resistance of NiWP and NiReP films remains almost constant until about 500 °C, the resistance of NiReP is maintained at a more constant level than that of NiWP. The results shown in Fig. 18 indicate that NiReP containing a large amount of refractory metal (44 at% rhenium) is most suitable for a thin film resistor for use at temperatures below 500 °C, Specific resistance and TCR values of the respective films are listed in Table 7. 

Redistribution of components can also occur under thermal stresses following packaging. In this example Sl-Cr thin film resistor elements were tested under high current load and they subsequently failed electrical tests. Visual examination under a light microscope Indicated some modification of the resistors had occurred under test conditions as shown in Figure 16. 

Figure 16. Light optical photograph of Si-Cr thin film resistors following stress at high currents.

Process Control of Vacuum-Deposited Nickel-Chromium for the Fabrication of Reproducible Thin-Film Resistors... 

We present here an effective way to manufacture a reproducible thin film resistor, using accepted statistical techniques. The process requirements, experimental techniques, process development and characterization, examples of control charts, their Interpretation for rapid appraisal and the Impact of statistical techniques on the production yields and future developments will be described. 

In monolithic Integrated circuit technology, all circuit elements are fabricated on, or within, a single crystal piece of semiconductor material by means of a sequential series of diffusion, photolithography and thin film processes. As a production method, generally where thin film resistors are required, the following process sequence Is defined ... 

The required specifications for our thin film resistor parameters are listed in Table I. Any product that deviates from the limits has to be reworked or scrapped. 

Figure 5.2.1 shows a photograph of an integrated surface-micromachined accelerometer, and Figure 5.2.2 is a close-up of the surface-micromachined polysilicon MEMS structure near the center of Figure 5.2.1. The structural material is 3 pm thick polysilicon and the IC process is bipolar and CMOS (BiCMOS) with thin film resistors. This structure thus combines bipolar transistors, CMOS, precision laser-trimmed resistors, and mechanical polysilicon [4],...

To reduce the amount of Pt used and in order to gain more signal, new technologies are used today to manufacture Pt sensing elements. Most Pt sensing elements are now in the form of thin-film resistors. This technology can produce... 

S.Q. Lud, M.G.. Nikolaides, 1. Haase, M. Fischer, and A.R. Bausch, Field effect of screened charges electrical detection of peptides and proteins by a thin-film resistor. ChemPhysChem. 7, 379-384 (2006). M.G. Nikolaides, S. Rauschenbach, S. Luber, K. Buchholz, M. Tornow, G. Abstreiter, and A.R. Bausch, Silicon-on-insulator based thin-film resistor for chemical and biological sensor applications. ChemPhysChem. 4, 1104-1106 (2003). 

Bruschi R, Cacialli R, Nannini A., and Neri B., Gas and vapour effects on the resistance fluctuation spectra of conducting polymer thin-film resistors. Sens. Actuators B, 18-19, 421-425, 1994. 

In many commercially available demand-mode ink-jet systems today, a thin-film resistor is substituted for the piezoelectric transducer. When high current is passed through this resistor, the ink in contact with it is vaporized, forming a bubble over the resistor [17]. This vapor bubble serves the same function as the piezoelectric transducer. This t5rpe of printer is referred to as a thermal ink-jet printer. 

Most of the experiments for detecting charged macromolecules with FEDs, reported in literature, have been realized using a transistor stmcture [11-36]. Recent successful experiments on the detection of charged biomolecules as well as polyelectrolytes with other types of FEDs, namely semiconductor thin film resistors [39-41], capacitive MIS [42] and EIS structures [43-50], have demonstrated the potential of these structures - more simple in layout, easy, and cost effective in fabrication - for studying the molecular interactions at the solid-liquid interface. A summary of results for the DNA detection with different types of FEDs is given in Table 7.1. 

Thin-film resistors usually make use of the first approach. For example, thin films (-10 nm thick) of indium tin oxide (ITO) are deposited onto glass, or sometimes steatite, substrates by sputtering or chemical vapor deposition (CVD). After deposition the films are patterned to achieve a large aspect ratio. If the substrate is in the form of a rod a spiral groove is cut into the film. 

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