Contact resistance to a thin semiconductor layer print file in pdf format. The difference between the fermi energy and the vacuum level is the workfunction. Herein, we investigate and analyze the effect of interfacial oxides and. Before discussing the behaviour of a metal semiconductor boundary, it is first necessary to introduce the concept of the work function. Rhoderick, 1988, clarendon press, oxford university press edition, in english 2nd ed. Before discussing the behaviour of a metalsemiconductor boundary, it is first necessary to introduce the concept of the work function. Whether a given metalsemiconductor junction is an ohmic contact or a schottky barrier depends on the schottky barrier height. Metalsemiconductor interfaces rectifying schottky junction nonrectifying ohmic contacts 3.
In addition to different device and circuit applications, schottky contacts can also be used as test vehicles for investigating the physical and electrical properties of a semiconductor material and its surfaces. Derivation of the diffusion current we start from the expression for the total current and then integrate it over the width of the depletion region. The semiconductor then behaves like a metal and for this reason is called a semimetal. Metalsemiconductor contacts are an obvious component of any semiconductor device. Attractive candidates for semiconductor device contacts minhyun lee, yeonchoo cho, kyungeun byun, keun wook shin, seonggeol nam. Theory when two substances are in contact, between them there is a charge. Work purpose the determination of the potential difference that appears at the contact surface between a metal and a semiconductor, potential difference that is known under the name of contact, or diffusion, bias.
It is well known that the quality of metalsemiconductor contacts plays an. Interfaces between metal and semiconductor may be found almost everywhere in contemporary electronics. Basically, there are two types of ms contacts that are widely used in semiconductor devices. The metal semiconductor ms contact is an important component in the performance of most semiconductor devices in the solid state. Brandt, sang bok kim, xizhu zhao, jun feng, tonio buonassisi, and roy g.
Metalsemiconductor interfaces rectifying schottky junction nonrectifying ohmic contacts 4. B is significantly higher than the thermal energy kt, the semiconductor is depleted near the metal and behaves as a schottky barrier. Metal semiconductor contacts energetic barriers are most often described by the electron affinity model eam. Sir jagadish chandra bose applied for a us patent for a metalsemiconductor diode in. Metal to semiconductor ms junctions are of great importance since they are present in every semiconductor device. Loya bell telephone laboratories, incorporated, murray hill, new jersey 07974, u. In modern semiconductor technology, contacts between semiconducting devices and the metal conductors that connect them with the rest of the system are of fundamental importance. It is thus a kind of schottky barrier detector, but with two schottky junctions. However, it was not until the twentieth century that the atomic theory of matter became firmly established as an unassailable, demonstrated fact. Characterization of metalsemiconductor contacts using. Metalintrinsic semiconductor band bending, a no applied bias, j 0. Therefore, its essential to understand the mechanisms and characteristics of how mosc operates. Today we will use band diagrams to describe what happens when we bring a metal into contact with a. Measurement of contact resistivity at metal tin sulfide sns interfaces chuanxi yang,1,a leizhi sun,1,a riley e.
Basic semiconductor material science and solidstate physics all terrestrial materials are made up of atoms. Often the metal is there just to serve as a contact to pn junctions in the semiconductor. Books, images, historic newspapers, maps, archives and more. This inevitably leads to metalsemiconductor contacts, and the impact of such junctions on the device must be considered. Gilbert ece 340 lecture 35 111611 ideal metalsemiconductor contacts what do the band diagrams look like. Search for library items search for lists search for contacts search for a library. Selfaligned via and trench for metal contact in iiiv semiconductor devices jun fei zhenga intel corporation, santa clara, california 95052 hilmi volkan demir nanotechnology research center, department of physics, and department of electrical and electronic engineering, bilkent university, bilkent, 06800 ankara, turkey. This whole concept of metalsemiconductor contacts in conventional semiconductors have already been studied and developed commercially for fabricating devices. Semiconductor device and material characterization dr. At the same time, such contacts cannot be assumed to have a resistance as low as that of two connected metals. General considerations for improving photovoltage in metal. Characterization of metal semiconductor contacts using circular transmission line measurement results. The lectures map onto the individual chapters in the book.
Twodimensional materials inserted at the metalsemiconductor interface. Metal semiconductor interfaces rectifying schottky junction nonrectifying ohmic contacts 4. A fundamental study of advanced metalsemiconductor contacts. Metalsemiconductors contacts engineering libretexts. At other times, the metalsemiconductor interface itself performs essential electronic functions. Barrier height ohmic contact schottky barrier schottky diode schottky contact. Semiconductors interfaces with metals skip to content skip to search. Higher schottky barrier leads to rectifying contact but in case it is close to zero it forms an ohmic contact. Unlimited viewing of the articlechapter pdf and any associated supplements and figures. Metal contacts to 2dmaterials for device applications. Lecture 17 metalsemiconductor junction march 14, 2007 contents. As with all of these lecture slides, i am indebted to dr. Brandt,2 sang bok kim,1 xizhu zhao,1 jun feng,1 tonio buonassisi,2 and roy g. Numerical simulation of metal interconnects of power.
Topics covered include the factors that determine the height of the schottky barrier, its currentvoltage characteristics, and its capacitance. Metalsemiconductor contact in organic thin film transistors article pdf available in journal of materials chemistry 1845. Derivation of the metalsemiconductor junction current 3. In this section we aim to look simply at the physical models that can be used to understand the electrical properties that can arise from these contacts, and then briefly discuss how deviations of these models can occur in. The energy needed to remove an electron from the metal is the work function, q. Then set up a personal list of libraries from your profile page by clicking on your user name at the top right of any screen. This second edition brings a greatly expanded treatment of th. Alan doolittle school of electrical and computer engineering. Topics covered include the factors that determine the height of the schottky ba. Generally the term ohmic contact implicitly refers to an ohmic contact of a metal to a semiconductor, where achieving ohmic contact resistance is possible but requires. The metal oxide semiconductor field effect transistor mosfet is one of the cornerstones of modern semiconductor technology. Metal semiconductor contact anchit biswas techno india,saltlake 2. Metaloxidesemiconductor mos fundamentals engineering.
A short discussion is also given of practical contacts and their application in. Doitpoms tlp library introduction to semiconductors. Ee311 saraswat ohmic contacts 5 for a tunneling contact the net semiconductor to metal current is given by jsm at k. Eects of thin oxide in metalsemiconductor and metal insulatorsemiconductor epigaas schottky diodes mantu kumar hudait a,b, s. In this chapter, we are concerned with the basic physical principles, electrical properties, and applications of the metal semiconductor contacts and devices. Metalsemiconductor contacts kasif nabi imi2015007 department of microelectronics indian institute of information technology allahabad 2nd november 2 november 2015 1 2. The metalsemiconductor ms contact is an important component in the performance of most semiconductor devices in the solid state. It is well known that the quality of metalsemiconductor contacts plays an important role in the performance of various semiconductor devices and integrated circuits. The present invention relates to a metalsemiconductor contact comprising a semiconductor layer and comprising a metallization applied to the semiconductor layer, a high dopant concentration being introduced into the semiconductor layer such that a nonreactive metalsemiconductor contact is formed between the metallization and the semiconductor layer. Highly efficient mis photoanodes require interfacial surface passivating oxides and high workfunction metals to produce a high photovoltage. Semiconductor materials, devices, and fabrication and the associated media content in the dvds provide an understanding of the materials, devices, and processing techniques used in the current microelectronics industry. Importance of metal semiconductor contacts is due to l ohmic metal semiconductor junctions e. Ohmic contacts to gallium arsenide devices materion. Metalsemiconductor contacts 1988 edition open library.
What does one have to do for a metalsemiconductor junction to become an ohmic contact. Metal semiconductor contacts are an obvious component of any semiconductor device. In order to set up a list of libraries that you have access to, you must first login or sign up. Properties of metal semiconductor contacts1 maintained constant by the electron dynamics in the and metal. Selfaligned via and trench for metal contact in iiiv. Metalsemiconductor contacts schottky contacts metal on lightly doped silicon rectifying ohmic contacts metal on heavily doped silicon low resistance 2 november. The term metal silicon contact includes silicidesi contacts. Pdf metalsemiconductor contact in organic thin film. Written for semiconductor technologists and physicists engaged in research on semiconductor interfaces, this text emphasizes practical implications wherever they are relevant to device technology. The doping profile is an important contributing factor to the currentvoltage relationship of a device. Rhoderick, metalsemiconductor contacts, clarendon press, oxford 1978. Nevertheless, eam explains several aspects depletion widths, capacitance, general iv shape, etc of ohmic and.
Measurement of contact resistivity at metaltin sulfide sns interfaces chuanxi yang, leizhi sun, riley e. Metalsemiconductor contacts fermi level pinning is the lack of barrier height modulation with metal work function due to either large density of intrinsic states. Derivation of the metalsemiconductor junction current. Metaltosemiconductor ms contacts are present in every semiconductor. The work function of a material is the energy required to remove an electron from the level of the chemical potential and give it enough energy to escape to infinity and arrive there with zero energy. Introduction formation of barrier current transport processes measurement of barrier height device structures ohmic contact. Williams, metalsemiconductor contacts, plenum press, 1984. In this chapter, the basic device physics, the electrical and transport properties, and the formation and characterization of various metalsemiconductor contacts are presented. The rectification property of metalsemiconductor contacts was discovered by ferdinand braun in 1874 using mercury metal contacted with copper sulfide and iron sulfide semiconductors. Fermi level position of ideal metal contacts to gaas. The 2 dvds include 32 lectures, approximately an hour each. Description and verification of the fundamental current. This book deals with the basic science of such contacts, and discusses the electrical properties that.
Ideal metalsemiconductor junction outside equilib rium reading assignment. Doitpoms tlp library introduction to semiconductors metal. Metalsemiconductor contacts and devices presents the physics, technology, and applications of metalsemiconductor barriers in digital integrated circuits. Numerical simulation of metal interconnects of power semiconductor devices maxim ershov, andrew tcherniaev, yuri feinberg, philipp lindorfer, william french, and peter hopper. Metal semiconductor contacts and devices issn, cohen. The physics and chemistry of the schottky barrier height. Rhoderick, 9780198593362, available at book depository with free delivery worldwide.
It is well known that the quality of metal semiconductor contacts plays an important role in the performance of various semiconductor devices and integrated circuits. The electrical conductivity of a semiconductor is very much affected. In particular, a large mismatch between the fermi energy of the metal and semiconductor can result is a highresistance rectifying contact. Recently, we have developed silicon carbide schottky barrier diodes that. The two terminals of moscapacitor consist of the main structures in mos devices and it is the simplest structure of mos devices. In this chapter, we are concerned with the basic physical principles, electrical properties, and applications of the metalsemiconductor contacts and devices. By having proper doping profiles and having a smooth interfacial contact layer. Download citation metalsemiconductor contacts in this chapter, the basic device physics, the electrical and transport properties, and the formation and.
Us7560783b2 metalsemiconductor contact, semiconductor. A short discussion is also given of practical contacts and their application in semiconductor technology, and a comparison is made with pn junctions. Eects of thin oxide in metalsemiconductor and metal. Department of electronics engineering, national chiao tung university, hsinchu, taiwan. As the name implies, the ms junction is that a metal and a semiconductor material are contacted closely. Indeed, the ancient greeks put this hypothesis forward over two millennia ago. Metalsemiconductor ohmic contacts stanford university. Krupanidhi a, a materials research centre, indian institute of science, bangalore 560 012, india. Metalsemiconductor contacts monographs in electrical and electronic engineering rhoderick, e.
Buy online, pick up in store is currently unavailable, but this item may be available for instore purchase. Metallic contact between mos2 and ni via au nanoglue cover page pdf available in small 1422 may 2018 with 150 reads how we measure reads. Writing a book on semiconductor device physics and design is never complete and probably never completely satisfying. Topics covered include the currentvoltage relationship, the capacitance of rectifying contacts, and practical methods of fabricating contacts. Twodimensional materials inserted at the metalsemiconductor. The general structure is a lightly doped ptype substrate, into which two regions, the source and the drain, both of heavily doped ntype semiconductor have been embedded. The zero of electrostatic potential has been taken with respect to the metal fermi level. A metalsemiconductormetal photodetector msm detector is a photodetector device containing two schottky contacts, i. They can behave either as a schottky barrier or as an ohmic contact dependent on the characteristics of the interface. We need to understand several key energies in the metal and the semiconductor the topmost energy is the vacuum level, e 0. At other times, the metal semiconductor interface itself performs essential electronic functions.
Fmde 6 where fs and fm are fermidirac distribution functions in metal and semiconductor. Nov 02, 2015 metalsemiconductor contacts kasif nabi imi2015007 department of microelectronics indian institute of information technology allahabad 2nd november 2 november 2015 1 2. Metal semiconductor interfaces rectifying schottky junction nonrectifying ohmic contacts 3. Metalinsulatorsemiconductor mis photoelectrodes offer a simple alternative to the traditional semiconductorliquid junction and the conventional pn junction electrode. How ever, irregularities of the metal film such as varia w. For a sufficiently large schottky barrier height, where. Metalsemiconductor contacts monographs in electrical and. Metal semiconductor contacts and devices issn kindle edition by cohen, simon s. Filled symbols represent sbh measured by iv method on ptype gaas, while open symbols are the. Printed in great britain current transport in metalsemiconductormetal msm structures s. Krupanidhi a, a materials research centre, indian institute of science, bangalore 560 012, india b central research laboratory, bharat electronics, bangalore 560 0, india received 7 september 1999. The activation energy is independent of the concentration. For example, a schottky diode can be used to study bulk defects and interface properties of a metalsemiconductor system.
Metalsemiconductor contacts 1988 edition open library donate. Schottky contacts using conducting probe atomic force microscopy cafm. In the case of ptype doping, the semiconductor is said to be degenerate when the fermi level is below the top of the valence band. Nonohmic contacts come in a number of forms, such as pn junction, schottky barrier, rectifying heterojunction, or breakdown junction. Metalsemiconductormetal photodetectors rp photonics.
1406 179 426 1277 487 622 697 624 1111 965 79 452 824 336 1283 706 248 526 1288 218 1135 21 1076 1198 245 370 1150 809 1332 596 1223