Method of plasma etching of dielectric layers of sic-si3n4
(57) Abstract:Usage: in microelectronics in the manufacture of integrated circuits at the stage of plasma etching, passivating coatings. The technical result of the invention is to eliminate the formation of fluorocarbon films, which leads to higher quality products. The invention consists in carrying out the process of plasma etching a two-layer pestiviruses coating of SiC-Si3N4in the gas mixture CF4-O2-Ar ratio of components in a three-dimensional parts (20-40) : 1 : 40-60), feeding RF power to the electrode-polictial, with subsequent cleaning of the surface in the gas mixture SF6-Ar, with the ratio of components in the bulk part 1:(40-60) in a single cycle without resultant deposition rates fluorocarbon polymer film on the surface of the semiconductor wafer. The invention relates to the field of microelectronics, in particular to the technology of IP to plasma etching processes.The process of plasma etching of layers of SiC-Si3N4is used during etching pestiviruses dielectric for dissection pads in the manufacture of thermocontrol.Known methods for the SiC (100) Thin Films in SF6. J. Of Electrochem. Soc., Vol. 136, No. 2, February 1989, p. 491-494. It consists in the fact that the SiC layer is etched in the plasma of SF6at a frequency of 13.56 MHz, power density 0,235 W/cm2and a pressure of 50...200 mtorr.The disadvantage of this method is the difficulty of vytravlivaetsya SiC grains with crystallographic orientation (100). When the etching these grains are formed pyramidal residues, which very slowly durablility.Known another method of etching a layer of SiC, as described in the Federal Republic of Germany patent DE 36033725 A1, declared 06.02.1986, published 13.08.1987,, H 01 L 21/308, which is plasma etching of the SiC layer in a mixture of CF4-O2containing at least 40 parts by volume OF2at a frequency of 13.56 MHz, a power density of 0.6 W/cm2, pressure 23...25 PA. The disadvantage of this method is the low selectivity etching of SiC to the photoresist. In fact, the photoresist is etched several times faster than SiC, which does not allow to use MDF for etching fairly thick SiC layers.The known method of plasma etching a layer of Si3N4described in the book "Plasma technology in the manufacture of VLSI", edited by N. Inspirace and D. brown, Moscow, "Mir", 1987, page 181. It consists in etching the layer of Si3N
FIELD: organic chemistry, chemical technology.
SUBSTANCE: invention relates to a method for purifying octafluorocyclobutane. Method is carried out by interaction of crude octafluorocyclobutane containing impurities with the impurity-decomposing agent at increased temperature and then with adsorbent that is able to eliminate indicated impurities up to the content less 0.0001 wt.-% from the mentioned crude octafluorocyclobutane. Impurity-decomposing agent comprises ferric (III) oxide and compound of alkaline-earth metal in the amount from 5 to 40 wt.-% of ferric oxide and from 60 to 95 wt.-% of compound of alkaline-earth metal as measured for the complete mass of the impurity-decomposing agent. Ferric (III) oxide represents γ-form of iron hydroxyoxide and/or γ-form of ferric (III) oxide. Impurity represents at least one fluorocarbon taken among the group consisting of 2-chloro-1,1,1,2,3,3,3-heptafluoropropane, 1-chloro-1,1,2,2,3,3,3-heptafluoropropane, 1-chloro-1,1,2,2,3,3,3-heptafluoropropane, 1-chloro-1,2,2,2-tetrafluoroethane, 1-chloro-1,1,2,2-tetrafluoroethane, 1,2-dichloro-1,1,2,2-tetrafluoroethane, hexafluoropropene and 1H-heptafluoropropane. Adsorbent represents at least one of representatives taken among the group including activated carbon, carbon molecular sieves and activated coal. Crude octafluorocyclobutane interacts with the mentioned impurity-decomposing agent at temperature from 250oC to 380oC. Invention proposes gas, etching gas and purifying gas including octafluorocyclobutane with purity degree 99.9999 wt.-% and above and comprising fluorocarbon impurity in the concentration less 0.0001 wt.-%. Invention provides enhancing purity of octafluorocyclobutane.
EFFECT: improved purifying method.
26 cl, 13 tbl, 10 ex
FIELD: organic chemistry, chemical technology.
SUBSTANCE: invention relates to a method for purifying octafluoropropane. Method is carried out by interaction of crude octafluoropropane comprising impurities with the impurity-decomposing agent at increased temperature and then with adsorbent that are able to remove indicated impurities up to the content less 0.0001 wt.-% from indicated crude octafluoropropane. The impurity-decomposing agent comprises ferric (III) oxide and compound of alkaline-earth metal in the amount from 5 to 40 wt.-% of ferric oxide and from 60 to 95 wt.-% of compound of alkaline-earth metal as measured for the complete mass of the impurity-decomposing agent. Ferric (III) oxide represents γ-form of iron hydroxyoxide and/or γ-form of ferric (III) oxide. Impurities represent at least one compound taken among the group consisting of chloropentafluoroethane, hexafluoropropene, chlorotrifluoromethane, dichlorodifluoromethane and chlorodifluoromethane. Adsorbent represents at least one substance taken among the group consisting of activated coal, molecular sieves and carbon molecular sieves. Crude octafluoropropane comprises indicated impurities in the amount from 10 to 10 000 mole fr. by mass. Invention proposes gas, etching gas and purifying gas comprising octafluoropropane with purity degree 99.9999 wt.-% and above and containing chlorine compound in the concentration less 0.0001 wt.-%. Invention provides enhancing purity of octafluoropropane.
EFFECT: improved purifying method.
13 cl, 11 tbl, 12 ex
FIELD: plasma-chemical treatment of wafers and integrated circuit manufacture.
SUBSTANCE: proposed device that can be used in photolithography for photoresist removal and radical etching of various semiconductor layers in integrated circuit manufacturing processes has activation chamber made in the form of insulating pipe with working gas admission branch; inductor made in the form of inductance coil wound on part of pipe outer surface length and connected to high-frequency generator; reaction chamber with gas evacuating pipe, shielding screens disposed at pipe base, and temperature-stabilized substrate holder mounted in chamber base. In addition device is provided with grounded shield made in the form of conducting nonmagnetic cylinder that has at least one notch along its generating line and is installed between inductor and pipe; shielding screens of device are made in the form of set of thin metal plates arranged in parallel at desired angle to substrate holder within cylindrical holder whose inner diameter is greater than maximal diameter of wafers being treated. Tilting angle, quantity, and parameters of wafers are chosen considering the transparency of gas flow screen and ability of each wafer to overlap another one maximum half its area. In addition substrate holder is spaced maximum four and minimum 0.6 of pipe inner diameter from last turn of inductance coil; coil turn number is chosen to ensure excitation of intensive discharge in vicinity of inductor depending on generator output voltage and on inner diameter of pipe using the following equation:
where n is inductance coil turn number; U is generator output voltage, V; Dp is inner diameter of pipe, mm.
EFFECT: enhanced speed and quality of wafer treatment; reduced cost due to reduced gas and power requirement for wafer treatment.
1 cl, 6 dwg, 1 tbl
FIELD: process equipment for manufacturing semiconductor devices.
SUBSTANCE: plasma treatment chamber 200 affording improvement in procedures of pressure control above semiconductor wafer 206 is, essentially, vacuum chamber 212, 214, 216 communicating with plasma exciting and holding device. Part of this device is etching-gas source 250 and outlet channel 260. Boundaries of area above semiconductor wafer are controlled by limiting ring. Pressure above semiconductor wafer depends on pressure drop within limiting ring. The latter is part of above-the-wafer pressure controller that provides for controlling more than 100% of pressure control area above semiconductor wafer. Such pressure controller can be made in the form of three adjustable limiting rings 230, 232, 234 and limiting unit 236 on holder 240 that can be used to control pressure above semiconductor wafer.
EFFECT: enhanced reliability of pressure control procedure.
15 cl, 13 dwg
FIELD: engineering of semiconductor devices.
SUBSTANCE: invention concerns method and device for etching dielectric, removing etching mask and cleaning etching chamber. In etching chamber 40 semiconductor plate 56 is positioned. Dielectric 58 made on semiconductor plate is subjected to etching, using local plasma, produced by special device for producing local plasma during etching process. Mask for etching 60 is removed by means of plasma from autonomous source 54, generated in device for producing plasma from autonomous source connected to etching chamber. Etching chamber after removal of semiconductor plate is subjected to cleaning, using either local plasma, or plasma from autonomous source. To achieve higher level of cleaning, it is possible to utilize a heater, providing heating for chamber wall.
EFFECT: increased efficiency.
2 cl, 4 dwg
FIELD: microelectronics, micro- and nano-technology.
SUBSTANCE: proposed method for producing submicron and nanometric structure includes formation of embossed structures on substrate surface, application of film to reduce embossed structure size to submicron and nanometric dimensions, and etching, anisotropic and selective relative to film material and source embossed layer, in chemically active plasma of structure obtained together with substrate material until embossed structure of submicron and nanometric dimensions, twice as deep as its width, is obtained.
EFFECT: provision for transferring mask pattern to bottom layer of substrate measured in terms of submicron and nanometric values.
2 cl, 3 dwg
FIELD: production of dirt-free laser mirrors.
SUBSTANCE: proposed method for producing dirt-free surfaces of materials chosen from group incorporating GaAs, GaAlAs, InGaAs, InGaAsP, and InGaAs on mirror facets of chip for GaAS based laser resonators includes shearing of laser mirror facet in ambient atmosphere incorporating normal air, dry air, or dry nitric media. Oxides and other pollutants produced in the course of ambient atmosphere impact on mirror facets are removed by dry etching in vacuum. Then natural nitride layer is grown on mirror facets using nitrogen treatment. Such facet treatment ensures minimized light absorption and surface recombination.
EFFECT: facilitated procedure, enhanced economic efficiency and yield due to high reproducibility.
37 cl, 5 dwg
FIELD: plasma reaction gas, its production and application.
SUBSTANCE: proposed plasma reaction gas has in its composition chain-structure perfluoroalkyne incorporating 5 or 6 atoms of carbon, preferably perfluorine-2-pentyne. This plasma reaction gas can be found useful for dry etching to produce precision structure, for plasma chemical precipitation from vapor phase, for producing thin film, and for plasma chemical incineration. Plasma reaction gas is synthesized by way of bringing dihydrofluoroalkyne or monohydroalkyne in contact with basic compound.
EFFECT: enhanced economic efficiency of highly selective gas production for plasma reaction on industrial scale.
FIELD: electronics; semiconductor devices and methods for etching structures on their wafers.
SUBSTANCE: plasmochemical etching of material is conducted by way of acting on its surface with ion flow of plasma produced from plasma forming gas filling evacuated camber, electron beam being used to act upon plasma forming gas for plasma generation. Constant longitudinal magnetic field with flux density of 20-40 Gs is built on axis, plasma-generating gas pressure is maintained within chamber between 0.01 and 0.1 Pa, and electron beam at current density of 0.1-1 A/cm2 ensuring ignition of beam-plasma discharge is used. Etching condition (energy and ion current density) can be controlled ether by modulating electron beam with respect to speed or by varying potential of discharge collector.
EFFECT: enhanced etching efficiency (speed) and quality of etching structures on semiconductor material surface: high degree of etching anisotropy preventing etching under mask, minimized material structure radiation defects brought in during etching.
2 cl, 1 dwg
FIELD: physics; electricity.
SUBSTANCE: etching system contains plasma-generating facilities for plasma generating in vacuum chamber, high-frequency displacement voltage source, supplying high-frequency displacement voltage to electrode-substrate, floating electrode opposite to electrode-substrate in vacuum chamber and supported in floating condition by electric potential, solid material placed on the side of the floating electrode directed to electrode-substrate to form film layer protecting from etching, and control unit for periodic supply of high-frequency voltage to floating electrode. Etching method includes repetition, in specified sequence, of substrate etching stage by means of etching gas supplied to vacuum chamber, and film layer formation stage protecting substrate from etching by sputtering of solid material opposite to substrate.
EFFECT: high etching selectivity when using mask as well as production of anisotropic profile and great etching depth.
22 cl, 7 dwg