A method of manufacturing an injecting contact to monosulfide samaria
(57) Abstract:Usage: during the formation of metallization of semiconductor devices on the basis of monosulfide Samaria. The inventive method is applied to the substrate monosulfide Samaria when the temperature of the substrate 100-200oC two-layer metallic coating speed , and the first layer of chromium, is applied directly to the substrate within 50-100, and the second layer, the cobalt - on top of the chrome layer within 300-400 C. 2 Il., 7 table. The invention relates to semiconductor electronics and can be used when forming the metallization of semiconductor devices on the basis of monosulfide samarium using methods of thermal evaporation, magnetron and ion-plasma sputtering, etc.The known method of forming ohmic contact to monosulfide Samaria, including the metal coating of cobalt (Co) on the substrate monosulfide Samaria, and is soldered to the plated wire output (and. C. Czechoslovakia N 238434, H 01 L 23/00, 1983)
The advantages of such contact are low resistance transition layer, good mechanical strength and stability. The combination of these properties is achieved by using the proposed method is a method of making ohmic contact to monosulfide samarium, representing a two-layer coating. C. the USSR N 1829769, H 01 L 21/283, 1991) as a first layer directly on the film monosulfide Samaria is covered with a layer of titanium over 50-100, then a layer of Nickel over the 300-OO with, and the layers are applied with the speed when the temperature of the substrate 100-200oC. This method is chosen for the prototype.However, this solution has several disadvantages: 1) low reproducibility of the characteristics of the contacts; 2) short life of contacts; 3) high contact resistance.The aim of the invention is to reduce the contact resistance with increasing stability and reproducibility characteristics of the contacts, to increase the service life of the contacts.This goal is achieved by the fact that in the proposed method of manufacturing an injecting contact by applying onto the substrate monosulfide Samaria when the temperature of the substrate 100-200oC with the speed of a two-layer metallic coating consisting of a first layer within 50-100, and the second layer within 300-400, new is the fact that the coating consists of a layer of chromium deposited directly on the substrate, and a layer of cobalt, nasenkorrektur on a substrate, and a layer of cobalt, of a thickness of from to .The proposed two-layer coating on a substrate at a temperature of 100-200oProvides an injecting contact, characterized superlinear current-voltage characteristic (I-V) and resistance management structure through the main injection of charge carriers from the received contact layer monosulfide Samaria, as well as high stability and reproducibility of the parameters and long life.The essence of the method consists in the following.Monosulfide samarium is one of the materials is very sensitive to mechanical deformations. Therefore, when forming the contact should be minimized to reduce mechanical tense, resulting in the deposition of the metal film of the contact material. To do this: 1) use of plastic materials; 2) to carry out the deposition at lower temperatures; 3) to exclude cyclic heat treatment.In addition, monosulfide Samaria in the presence of oxygen is oxidized, resulting in either drastically limit the contact with air, or use the sublayer strong getter. As a getter us ispolzovatblizhny characteristics, and lower the work function of the metal into the semiconductor for carriers (see also Fomenko C. C. Emission properties of materials. Kiev, Naukova Dumka, 1970 148 C. ) Getter action of chromium is to reduce the partial pressure of oxygen during the deposition due to desorption chemisorbing layer of oxide on the surface of monosulfide Samaria as a result of chemical reaction with chromium her.Chrome also has a high plastic properties. However, he has a fairly high resistance to 13.2 mcomm at 20o(Smits K. J. The metals. M. metallurgy, 1980, 448 C.) Therefore, the thickness of the chromium layer to be selected in such a way that the manifestation of getter properties, this layer had little resistance.As the second layer contact us selected cobalt. It is a plastic metal, provides a low resistance when the thickness from to not corrode under cyclic mechanical loads two-layer plated chrome-cobalt does not change their electrophysical and mechanical characteristics. Deposition of both layers is performed at the temperature of the substrate 100-200oC. At lower temperatures, rapidly deteriorating the adhesion of the contact, and at a higher uwee. The use of double-layer deposition of chromium-cobalt allowed to obtain an injecting contact with low resistance decreases with increasing voltage applied to the structure of the contact monosulfide Samaria, with high reproducibility, stability and enhanced life.An injecting contact in comparison with the ohmic possesses a number of advantages, both physical and technical nature. It is known (see Lampert, M., mark P. Injection currents in solids. M. Mir, 1973, 416 S.) that the injection of carriers from the contact in the solid body can lead to an improvement of a number of parameters, the most important of which is performance. In our case, the use of an injecting contact to monosulfide samarium can improve this important parameter. In addition, when the voltage is rising due to sverginate WAH decreases the resistance patterns contact monosulfide Samaria, and this resistance change is controlled by the applied voltage, which can be important in specific applications monosulfide Samaria as the strain gauge.The proposed solution allows comparison with the prototype to increase the stability of contact to manage it with themperature (from 100 to 200oWith the substrate) the application of metals due to the high getter activity of chromium and a low work function of electrons. This increases the reproducibility of the contact and decreases its resistance.The variation of the thickness of the getter layer and the contact layer made it possible to find the optimum conditions to achieve the goal, and the temperature range allowed us to obtain an injecting contact without residual stress, which is especially important when using monosulfide Samaria as the strain gauge.In Fig. 1 shows the volt-ampere characteristic (double logarithmic scale) patterns contact monosulfide Samaria, obtained by the proposed method.In Fig. 2 presents the dependence of the degree WAH dlnI/dlnV from tension, in double logarithmic scale.Getting the contacts of the proposed method was carried out in a vacuum unit UVR-SM when the vacuum 510-6Torr. The volt-ampere characteristic of the structure shown in Fig. 1. In Fig. 2 shows the dependence of the degree WAH (differential tilt WAH) adlnI/dlnV tension in double logarithmic scale. This dependence pne in semiconductors. Kiev, Naukova Dumka, 1981, 256 C.), to fix ohmic ( a 1) and injection ( a > 1) plots. Of the dependence in Fig. 2 should the range of obecnosci contact from 1.0 V to 30 C.In table. 1 shows the study of the influence of the modes of deposition of chromium at fixed modes of deposition of cobalt (time spraying tco=350oC, the speed of deposition temperature deposition T=150oC) resistance range resistance layout of strain gages.Measurement of resistance of the layout of the strain gauges with contacts were made with an applied voltage of V=0.1 V, where the injection of carriers from the contact was still weak, and ran Ohm's law ( 1). For each mode was determined by the average value of the resistance in the party by the formula
< / BR>where n is the number of samples in the party, Rarrthe resistance of the sample.In our experiments the value of n ranged from 20 to 30. The deviation of the resistance R from the average value was determined by the formula
< / BR>The average value of the deviation resistance was determined by the following formula
< / BR>From the data table. 1 shows that the rate of deposition of chromium and time of deposition 50-100 with the average resistance of mock-UPS and medium rejected is Balta at fixed modes of deposition of chromium (time spraying tcr=70 C, the deposition rate , the temperature of deposition T=150oC) resistance range resistance layout of strain gages.From the data table. 2 it follows that the rate of deposition of cobalt and time of deposition 300-400 with the average resistance of the layouts and the average value of the deviation of the resistance minimum.In table. 3 research data on the effect of temperature regimes of deposition of the contact.From table. 3 shows that the optimum temperature of the substrate is in the range from 100 to 200oC.Below is the reproducibility of the resistance layout of strain gages, obtained by metallization contacts on one of the best available technologies (PL. 4) and sub-optimal technology (PL. 5).From the data table. 4 and 5 it follows that the nonoptimality of the regime applying only sublayer of chromium leads to a decrease of reproducibility and increased resistance layouts.The study of the stability and lifetime of the layout of the strain gauge with contacts, obtained by optimal technology ( tcr= 70 c, tco= 350 c, Tdastardly=150oC) presented in table. 6 and 7. Here Rarris determined by the formula
< / BR>where Rarr. 0the beginning of the table shows within 4 h care resistance did not exceed 0.25 (table. 6). The resistance change within 60 days did not exceed 0,35 (PL. 7).As follows from Fig. 1, the resistance of the layout of the strain gauge at V=1.0 is 190 Ohms, V=10.0 V 60 Ω and V=20,0 In 42,0 Ohms. In other words, by using the applied voltage can control the resistance of the layout of the strain gauge, in this case within 40-2000 Ohms. A method of manufacturing an injecting contact to monosulfide Samaria, including the application of a two layer metallic coating on the substrate monosulfide Samaria, and the first layer is applied directly to the substrate during the 50 100, and the second layer within 300 400 rate of deposition of the layers 10 and 20 and the temperature of the substrate 100 200o, Characterized in that the first layer using chrome, as well as a second layer of cobalt.
FIELD: micro- and nanoelectronics, micro- and nanomechanics where insulated conductors are used.
SUBSTANCE: proposed method for filling pockets in solid body with conducting material includes coating of solid-body surface, bottom, and side walls of mentioned pockets with first layer that functions as barrier material preventing diffusion of mentioned conducting material in solid body; application of second layer onto first one that functions as wetting layer for conducting material; application of third layer by way of physical or chemical deposition onto third one from gas phase that has in its composition mentioned conducting material; coating of third layer with fourth one that also incorporates conducting material; melting of conducting material by heating and profile leveling; material melting by heating is conducted after applying third layer and fourth layer is applied by any method of physical deposition from gas phase, chemical deposition from gas phase, chemical deposition from solution, electrochemical deposition, or chemical-mechanical deposition.
EFFECT: facilitated procedure, enlarged functional capabilities.
12 cl, 17 dwg
SUBSTANCE: invention is attributed to microelectronics and can be used in production of semiconductor devices and integral circuits. Essence of invention: in the method of attaching silicon chip to chip holder, chip seating surface is successively sputtered with two titan-germanium metals, and chip to chip holder soldering is carried out at temperature of 280-300°C.
EFFECT: improvement of chip with chip-holder contact reliability and stability of attachment process.
SUBSTANCE: method involves notching in bulk of a silicon wafer and silicone removing from the wafer back to uncover notch bottoms. Notching enables silicone pattern formation to represent hollow cell walls that is followed with wall-through oxidation to form a dielectric SiO2 conduit system. Silicon removing from the back of the wafer can be conducted by the deep plasma etch process.
EFFECT: high strength of the insulating element which can be used for manufacturing various MEMS devices in bulk of a standard silicon wafer.
2 cl, 13 dwg
SUBSTANCE: in manufacturing method of multi-level copper metallisation of VLSIC, which involves application operations of metal and dielectric layers, photolithography and selective etching of those layers, chemical mechanical polishing of dielectric layers, to plate of silicium, which is coated with dielectric material with vertical conductors of underlying structure, which protrude on its surface, there applied is multi-layered conducting film consisting of adhesive barrier, etched and auxiliary layers; grooves are formed in auxiliary layer before etched layers by electrochemical method; copper horizontal conductors are grown inside grooves in open sections of etched layer till grooves are fully filled; the second auxiliary layer is applied to surface of plate, and in that layer holes are made to the surface of horizontal copper conductors; vertical copper conductors are grown by electrochemical method in open sections of horizontal conductors till holes for vertical conductors are fully filled; then, auxiliary layers are removed; conducting layers between horizontal copper conductors are removed; dielectric layers are applied to surface of the plate by smoothing and filling methods, and then dielectric material layers are removed above vertical conductors by means of chemical and mechanical polishing method.
EFFECT: improving quality of copper conductors.
16 cl, 11 dwg, 1 tbl
FIELD: instrument making.
SUBSTANCE: invention relates to semiconductor devices production process, in particular to technology of making contacts with lowered resistance. In method of semiconductor device making contacts are formed on basis of platinum. For this film of platinum with thickness of 35-45 nm is applied by electron-beam evaporation on silicon substrate, heated prior to 350 °C, at rate of deposition of 5 nm/min. Then heat treated in three stages: 1 step is carried out at temperature of 200 °C for 15 minutes, 2 step is carried out at temperature of 300 °C for 10 minutes and 3 stage is at 550 °C for 15 min in forming gas, with mixture of gases N2:H2=9:1.
EFFECT: proposed method of semiconductor device making provides reduced contact resistance, high technological effectiveness, improved parameters of devices, high quality and yield.
1 cl, 1 tbl
SUBSTANCE: invention relates to the field of semiconductor production technology, namely to a technology of low-resistance silicide layers formation. The method of semiconductor devices manufacture includes formation of an amorphous layer by silicon ion implantation on the silicon plate with the energy of 50 keV and dose⋅ of 5⋅1015 cm-2, at the substrate temperature of 25°C. Prior to the palladium layer application, the substrate is sequentially etched in nitric, sulfuric and hydrofluoric acid, then washed with deionized water. The palladium layer is applied at a temperature of 25-100°C, with a thickness of 0.1 microns at a rate of 1.5 nm/sec. After application of the palladium layer, heat-treated under vacuum is conducted at a pressure of (2-8)⋅ 105 mm Hg, temperature of 250°C for 20-30 minutes. As a result, palladium silicide Pd2Si is formed.
EFFECT: invention reduces drag, improves process efficiency, improves parameters, improves quality and increases yield percentage.
SUBSTANCE: method of increasing the threshold barrier voltage of a transistor based on gallium nitride (GaN), which includes creating gate p-GaN mesa on the surface of the silicon wafer with epitaxial heterostructure of GaN/AlGaN/GaN type, inter-instrument mesa-isolation, forming ohmic contacts to the areas of the transistor drain and source, forming a two-layer resistive mask by lithographic methods, cleaning of the surface of the semiconductor, deposition of thin films of gate metallization, removing of the plate from the vacuum chamber of the evaporator, removal of the resistive mask, prior to the evaporation of thin films of gate metallization the plate is subjected to treatment in an atmosphere of atomic hydrogen for t=10-60 seconds at a temperature of t=20-150°C and flow density of hydrogen atoms on the surface of the plate, equal to 1013-1016 at. cm-2 c-1.
EFFECT: increase in the threshold barrier voltage of the GaN transistor when applying barrier metal films to the p-GaN gate area with a high electronic work function.
5 cl, 3 dwg