Resistor Test Research Articles

The spreading resistance error in the vertical Kelvin test resistor structure for the specific contact resistivity

The spreading resistance error in the vertical Kelvin test resistor (VTR) structure is studied based on an analytic approach. It is found that it is always less than the error existing in the horizontal test structures and can be expressed as the product of the sheet resistance and the square of the junction depth of the conductor resistor divided by a factor approximately equal to 2.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

4734641 Method for the thermal characterization of semiconductor packaging systems

A method for determining the thermal characteristics of a semiconductor packaging system is provided which uses a platinum resistor test unit. The platinum resistor is preferably sized to approximate the dimensions of the semiconductor device for which the package was designed, and is installed within the package. The packaged resistor is then thermally calibrated at a plurality of temperature levels to generate a linear temperature versus resistance graph or equation corresponding thereto. Next, voltage is applied to the packaged resistor causing such resistor to "self heat." Its resistance is calculated, and the temperature corresponding thereto is obtained from the graph or equation. Such temperature is the surface temperature of the resistor. This temperature may then be used to calculate the temperature gradient from the inside of the package to any reference point on or near the outside of the package, the temperature of which has been previously determined.

Thermal analysis of electromigration test structures

Analytical expressions are derived for estimating the temperature profile along a straight-line resistor test structure due to the joule heating generated by a high current-density stress, such as is used in accelerated stress tests to characterize metallizations for electromigration. It is shown how an improved estimate of the mean metallization stress temperature may be made and how the thickness and thermal conductivity of the underlying electrical insulator affect the temperature profile of the metallization. Recommendations for the design of electromigration test structures are developed that will promote reduced temperature gradients in the metallization during stress testing and improved reproducibility of electromigration characterizations.

Modeling and measurement of contact resistances

This paper presents a generalized model of ohmic contacts and a unified approach for the accurate extraction of specific contact resistivity (ρ <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">c</inf> ) for ohmic contacts from measured contact resistance using the cross bridge Kelvin resistor, the contact end resistor, and the tranmsission line tap resistor test structures. A general three-dimensional (3-D) model of the contacts has been developed from the first principles and has been reduced to 2-D, 1-D, and 0-D (one lump) models with the necessary approximations. It is shown that the conventional I-D models overestimate the value of ρ <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">c</inf> because of the parasitic resistance due to 2-D current flow around the periphery of the contact window. Using 2-D simulations, we have accurately modeled the current crowding effects and have extracted accurate values of ρ <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">c</inf> independent of contact size and the test structure type. A theory of scaling of contacts has been developed and is applied to commonly used structures. A universal set of curves has been derived for each particular contact resistance test structure and, given the geometry of the structure, these allow accurate determination of ρ <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">c</inf> , Without the actual use of the 2-D simulator. Experimental and theoretical accuracy of the three test structures has been compared. Accurate values of ρ <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">c</inf> for various contact materials to n <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+</sup> and ρ <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+</sup> Si have been determined. The data confirm that in the past researchers have overestimated ρ <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">c</inf> , and that ρ <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">c</inf> will not limit device performance even with submicrometer design rules.

Low ohmic contact to silicon with a magnesium/aluminum layered metallization

A low-contact-resistance, low-resistivity magnesium aluminum (Mg/Al) layered metal is described. Measurements according to the transmission line model showed a specific contact resistivity of 2.2 × 10−7 Ω cm2 to an n-type planar silicon test resistor. A barrier height of 0.46 eV for Mg-nSi contacts was confirmed for Schottky diodes.

Particle Damage Effects in GaAs JFET Test Structures

Damage measurements on specially designed ion implanted GaAs JFET, resistor, and Hall-effect test structures using neutrons, protons, helium ions, and sulfur ions have shown the relationship of damage rates with particle type and implant dose.

Ion-implanted, electron-beam annealed TiN films as diffusion barriers for Al on Si shallow junctions

TiN films are prepared by N+2 implantation onto evaporated Ti films. By properly selecting the Ti thickness, implantation energy and annealing process, a TiSi2/TiN structure can be formed. In particular, in this work a postimplant rapid isothermal annealing is carried out at 800 °C for 30 s by using an electron beam. The effectiveness of these TiN films as a diffusion barrier is then evaluated when put in contact with a thick Al overlayer. Both the TiN/Al and TiSi2/TiN/Al contact structures are tested, after thermal treatments up to 600 °C, on shallow junction diodes and four terminal resistor test patterns for contact resistance measurements. The electrical performances of the TiSi2/TiN/Al contact system are found to be good, although the degradation resistance is slightly worse than the one observed on similar structures annealed in a vacuum furnace after the nitrogen implantation.

Contact resistivity of silicon/silicide structures formed by thin film reactions

Abstract Contact resistance measurements were carried out on n + -Si/Pd 2 Si, n + -Si/NiSi, n + -Si/TiSi 2 , p + -Si/Pd 2 Si, p + -Si/NiSi and p + -Si/TiSi 2 structures using fourterminal resistor test patterns. Parasitic effects due to lateral current crowding at the entrance of the contact were taken into account in an accurate interpretation of the experimental results. The effect of silicide side-walls within the silicon is discussed and corrections for this effect are presented. For comparison, data obtained on test patterns conforming to the standard transmission line model are reported. Finally, the active dopant concentration profiles near the n + -SiTiSi 2 , n + -SiPd 2 Si and p + -SiTiSi 2 interfaces were measured in order to derive the theoretical values of the contact resistivity and to compare these values with the experimental results.

A further comment on "Determining specific contact resistivity from contact end resistance measurements"

The purpose of this comment is to contribute to a better understanding of the influence of lateral current crowding, sheet resistance, and interface pitting in the determination of the interface contact resistivity in four terminal resistor test patterns, for two different metallization schemes, i.e., 1Al/n+Si and (Al + 1.5-percent Si)/n+Si.

Electrical Characterization of Ion Imiplanted, Thermally Annealed TiN Films Acting as Diffusion Barriers on Shallow Junction Silicon Devices

ABSTRACTTiN films prepared by implantation onto evaporated Ti layers are tested as diffusion barriers in contact with a thick Al overlayer. Both the TiN/Al and TiSi2/TiN/Al contact structures are evaluated, after thermal treatments up to 600 C, on shallow junction diodes and four terminal resistor test patterns for contact resistance measurements. It is shown that, upon annealing at 600 C, the TiSi2/TiN/Al contact system still exhibits excellent electrical performances. The degradation is found to depend on TiSi2 thickness and contact area.

Lateral current crowding effects on contact resistance measurements in four terminal resistor test patterns

Lateral current crowding effects on contact resistance measurements in four terminal resistor patterns are discussed by using a computer model based on a three-dimensional resistor network. The model is then applied to extrapolate the contact resistivity in n+, p+ silicon/titanium silicide interfaces. Values in agreement with the ones predicted by the field and thermionic field emission theory are obtained.

A numerical analysis of various cross sheet resistor test structures: J. M. David and M. G. Buehler Solid State Electronics,20, p.539 (1977)

A numerical analysis of various cross sheet resistor test structures: J. M. David and M. G. Buehler Solid State Electronics,20, p.539 (1977)

The Current Limiting Capability of Diffused Resistors

An experimental evaluation of the current limiting capability of dielectrically isolated diffused resistors at transient ionizing dose rates up to 6×1012 rads(Si)/ sec is presented. Existing theoretical predictions of the transient response of diffused resistors are summarized and compared to the experimentally measured values. The test resistors used allow the effects of sheet resistance and geometry on the transient response to be determined. The experimental results show that typical dielectrically isolated diffused resistors maintain adequate current limiting capability for use in radiation hardened integrated circuits.

Bridge and van der Pauw Sheet Resistors for Characterizing the Line Width of Conducting Layers

It is shown that the line width of conducting layers can be computed from simple d‐c electrical measurements made on bridge and van der Pauw shaped test structures. A compact six‐contact, cross‐bridge sheet resistor test structure was developed to make this measurement directly. Line widths measured on boron nitride diffused layers indicate that the method is sensitive to width variations of the order of ±0.1 μm (±4 μin.)

A numerical analysis of various cross sheet resistor test structures

Various four-terminal cross sheet resistor test structures were analyzed to determine the effect of the contact arm width and length on the measured sheet resistance. A nine-point finite difference approximation to the Laplace equation was used with a six-resistor equivalent circuit to solve for the sheet resistance measurement error. The error indicates the difference between the true sheet resistance and the sheet resistance calculated from the van der Pauw formula. The analysis demonstrates that many novel designs are possible. In particular, the Greek-cross sheet resistor is a valid van der Pauw test structure if the arm length is greater than the arm width. This test structure is important in that it allows the accurate measurement of the sheet resistance of a very small region whose width is limited only by the fabrication technology.

A numerical analysis of various cross sheet resistor test structures : J. M. David and M. G. Buehler. Solid-St. Electron.20, p. 539 (1977)

A numerical analysis of various cross sheet resistor test structures : J. M. David and M. G. Buehler. Solid-St. Electron.20, p. 539 (1977)

The effects of ionizing radiation on diffused resistors

A theoretical examination of the effects of ionizing radiation on diffused resistors performed to ascertain the feasibility of their use in hardened dielectrically isolated integrated circuits is described. The two basic effects — conductivity modulation, which is generally insignificant or can easily be rendered so, and photocurrent generation, the consequences of which essentially determine the diffused resistor hardness — are studied. Results indicate that typical dielectrically isolated diffused resistors are quite invulnerable to ionizing radiation. Design guidelines to achieve optimum hardness are implied. Initial findings of radiation experiments performed on a diffused resistor test chip are reported. When transient leakage dissociated with the resistor structures is accounted for, the results substantiate the primary conclusions of the theoretical study.

High Stability Cosputtered Ta-50 At. %Al Alloy Film Resistors

The potential of sputtered Ta-50 at. % Al alloy films for tantalum integrated circuit resistor applications was evaluated. Test resistors covering a range of 25 to 1000 \Omega /o were fabricated from 900 to 1500 \AA thick alloy films (on ceramic substrates) using two different anodic thinning-stabilization heat treatment process sequences. The effect of initial thickness and process sequence on stability was determined by accelerated aging, thermally at 250 and 15O°C, and under DC power at 2 watts (6.2 watts/cm2). It was found that the Ta-50 at. % Al alloys offer outstanding potential for circuit and R-C network applications requiring highly stable 25 to 1000 \Omega /o film resistors. For such applications, the alloys exhibit a combination of attractive characteristics which include: 1) the ability to readily adjust the sheet resistance by anodization; 2) the maintenance of a relatively constant temperature coefficient of resistance; 3) excellent stability during both thermal and power aging tests.

Remote testing of resistance thermometers

If certain design requirements are met and the temperature coefficient of resistance of the test resistor has a definite value, it is possible to provide remote testing of the condition of a temperature thermometer. In this testing the normalized test signal voltage is virtually independent of the measured temperature.

Resistance comparator for measuring changes in the resistance of wires

This paper describes an instrument designed to measure the ratio of resistance between a standard stable resistor and a test resistor. The ratio measurement is reproducible to within two parts in 105. Since the measurement is made upon a comparative basis extreme precautions regarding absolute temperature control of the testing chamber need not be taken, provided that both the test and standard specimens are at the same temperature and are subjected to identical thermal gradients. The measuring bridge comprises the standard and test specimens which are linked to the primary and secondary windings of a current transformer. The current in the test resistor can be changed in definite proportions by a ratio transformer. The resistance ratio of the two resistors is given directly by the setting on this device when the circuits are balanced. The design of the test specimen is such that it can be removed from the testing chamber and replaced, after heat treatment, without incurring errors owing to changes in contact resistance and thermal e.m.fs.