DE2730156A1 - GAS-PLASMA ETCHING OF ALUMINUM AND ALUMINUM OXIDE - Google Patents
GAS-PLASMA ETCHING OF ALUMINUM AND ALUMINUM OXIDEInfo
- Publication number
- DE2730156A1 DE2730156A1 DE19772730156 DE2730156A DE2730156A1 DE 2730156 A1 DE2730156 A1 DE 2730156A1 DE 19772730156 DE19772730156 DE 19772730156 DE 2730156 A DE2730156 A DE 2730156A DE 2730156 A1 DE2730156 A1 DE 2730156A1
- Authority
- DE
- Germany
- Prior art keywords
- aluminum
- etching
- gas
- layer
- plasma
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 title claims description 37
- 229910052782 aluminium Inorganic materials 0.000 title claims description 37
- 238000001020 plasma etching Methods 0.000 title claims description 16
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 title claims description 11
- 238000005530 etching Methods 0.000 claims description 45
- 238000000034 method Methods 0.000 claims description 18
- 239000000460 chlorine Substances 0.000 claims description 10
- KZBUYRJDOAKODT-UHFFFAOYSA-N Chlorine Chemical compound ClCl KZBUYRJDOAKODT-UHFFFAOYSA-N 0.000 claims description 7
- 239000004065 semiconductor Substances 0.000 claims description 5
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 claims description 4
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 claims description 4
- 229910052796 boron Inorganic materials 0.000 claims description 4
- 229910052801 chlorine Inorganic materials 0.000 claims description 4
- 238000004519 manufacturing process Methods 0.000 claims description 3
- 239000000758 substrate Substances 0.000 claims description 3
- FAQYAMRNWDIXMY-UHFFFAOYSA-N trichloroborane Chemical compound ClB(Cl)Cl FAQYAMRNWDIXMY-UHFFFAOYSA-N 0.000 claims 1
- 239000010410 layer Substances 0.000 description 22
- 239000007789 gas Substances 0.000 description 20
- 229920002120 photoresistant polymer Polymers 0.000 description 7
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 4
- 239000011261 inert gas Substances 0.000 description 4
- 235000012771 pancakes Nutrition 0.000 description 4
- 231100000572 poisoning Toxicity 0.000 description 4
- 230000000607 poisoning effect Effects 0.000 description 4
- 229910018516 Al—O Inorganic materials 0.000 description 3
- 239000007795 chemical reaction product Substances 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- 235000012431 wafers Nutrition 0.000 description 3
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 2
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 2
- 229910052786 argon Inorganic materials 0.000 description 2
- 229910052710 silicon Inorganic materials 0.000 description 2
- 239000010703 silicon Substances 0.000 description 2
- YPSXFMHXRZAGTG-UHFFFAOYSA-N 4-methoxy-2-[2-(5-methoxy-2-nitrosophenyl)ethyl]-1-nitrosobenzene Chemical compound COC1=CC=C(N=O)C(CCC=2C(=CC=C(OC)C=2)N=O)=C1 YPSXFMHXRZAGTG-UHFFFAOYSA-N 0.000 description 1
- 102100021569 Apoptosis regulator Bcl-2 Human genes 0.000 description 1
- WKBOTKDWSSQWDR-UHFFFAOYSA-N Bromine atom Chemical compound [Br] WKBOTKDWSSQWDR-UHFFFAOYSA-N 0.000 description 1
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 1
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 1
- 229910021555 Chromium Chloride Inorganic materials 0.000 description 1
- 101000971171 Homo sapiens Apoptosis regulator Bcl-2 Proteins 0.000 description 1
- 229910004298 SiO 2 Inorganic materials 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 150000007513 acids Chemical class 0.000 description 1
- GDTBXPJZTBHREO-UHFFFAOYSA-N bromine Substances BrBr GDTBXPJZTBHREO-UHFFFAOYSA-N 0.000 description 1
- 229910052794 bromium Inorganic materials 0.000 description 1
- 239000003638 chemical reducing agent Substances 0.000 description 1
- 239000011651 chromium Substances 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 238000004132 cross linking Methods 0.000 description 1
- 238000000151 deposition Methods 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 239000007772 electrode material Substances 0.000 description 1
- 230000003628 erosive effect Effects 0.000 description 1
- 230000005284 excitation Effects 0.000 description 1
- 238000011010 flushing procedure Methods 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 229910000041 hydrogen chloride Inorganic materials 0.000 description 1
- IXCSERBJSXMMFS-UHFFFAOYSA-N hydrogen chloride Substances Cl.Cl IXCSERBJSXMMFS-UHFFFAOYSA-N 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 238000010849 ion bombardment Methods 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 231100000614 poison Toxicity 0.000 description 1
- 230000007096 poisonous effect Effects 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 239000011241 protective layer Substances 0.000 description 1
- 239000010453 quartz Substances 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
- 239000000376 reactant Substances 0.000 description 1
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 description 1
- 229910010271 silicon carbide Inorganic materials 0.000 description 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
- 239000011780 sodium chloride Substances 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 238000007704 wet chemistry method Methods 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23G—CLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS
- C23G5/00—Cleaning or de-greasing metallic material by other methods; Apparatus for cleaning or de-greasing metallic material with organic solvents
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23F—NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25
- C23F4/00—Processes for removing metallic material from surfaces, not provided for in group C23F1/00 or C23F3/00
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer
- H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic Table or AIIIBV compounds with or without impurities, e.g. doping materials
- H01L21/30—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26
- H01L21/31—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26 to form insulating layers thereon, e.g. for masking or by using photolithographic techniques; After treatment of these layers; Selection of materials for these layers
- H01L21/3105—After-treatment
- H01L21/311—Etching the insulating layers by chemical or physical means
- H01L21/31105—Etching inorganic layers
- H01L21/31111—Etching inorganic layers by chemical means
- H01L21/31116—Etching inorganic layers by chemical means by dry-etching
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer
- H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic Table or AIIIBV compounds with or without impurities, e.g. doping materials
- H01L21/30—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26
- H01L21/31—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26 to form insulating layers thereon, e.g. for masking or by using photolithographic techniques; After treatment of these layers; Selection of materials for these layers
- H01L21/3105—After-treatment
- H01L21/311—Etching the insulating layers by chemical or physical means
- H01L21/31144—Etching the insulating layers by chemical or physical means using masks
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer
- H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic Table or AIIIBV compounds with or without impurities, e.g. doping materials
- H01L21/30—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26
- H01L21/31—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26 to form insulating layers thereon, e.g. for masking or by using photolithographic techniques; After treatment of these layers; Selection of materials for these layers
- H01L21/3205—Deposition of non-insulating-, e.g. conductive- or resistive-, layers on insulating layers; After-treatment of these layers
- H01L21/321—After treatment
- H01L21/3213—Physical or chemical etching of the layers, e.g. to produce a patterned layer from a pre-deposited extensive layer
- H01L21/32133—Physical or chemical etching of the layers, e.g. to produce a patterned layer from a pre-deposited extensive layer by chemical means only
- H01L21/32135—Physical or chemical etching of the layers, e.g. to produce a patterned layer from a pre-deposited extensive layer by chemical means only by vapour etching only
- H01L21/32136—Physical or chemical etching of the layers, e.g. to produce a patterned layer from a pre-deposited extensive layer by chemical means only by vapour etching only using plasmas
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer
- H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic Table or AIIIBV compounds with or without impurities, e.g. doping materials
- H01L21/30—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26
- H01L21/31—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26 to form insulating layers thereon, e.g. for masking or by using photolithographic techniques; After treatment of these layers; Selection of materials for these layers
- H01L21/3205—Deposition of non-insulating-, e.g. conductive- or resistive-, layers on insulating layers; After-treatment of these layers
- H01L21/321—After treatment
- H01L21/3213—Physical or chemical etching of the layers, e.g. to produce a patterned layer from a pre-deposited extensive layer
- H01L21/32139—Physical or chemical etching of the layers, e.g. to produce a patterned layer from a pre-deposited extensive layer using masks
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Physics & Mathematics (AREA)
- Manufacturing & Machinery (AREA)
- Computer Hardware Design (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Power Engineering (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- General Physics & Mathematics (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Mechanical Engineering (AREA)
- Organic Chemistry (AREA)
- Metallurgy (AREA)
- Materials Engineering (AREA)
- Plasma & Fusion (AREA)
- Inorganic Chemistry (AREA)
- Drying Of Semiconductors (AREA)
- ing And Chemical Polishing (AREA)
Description
Die Erfindung betrifft das Gasplasma-Ätzen von Aluminium und Aluminiumoxid und besondere das Ätzen durch eine Photoresist-Maske z.B. bei der Herstellung von Halbleiter-Bauelementen.The invention relates to the gas plasma etching of aluminum and Aluminum oxide and, in particular, etching through a photoresist mask, e.g. in the manufacture of semiconductor components.
Gasplasma-Ätzung wird gegenüber von Naßchemie aus verschiedenen Gründen bevorzugt. Beispielsweise ist der Vorgang sauberer, er kann vereinfacht werden, wobei eine verbesserte Auflösung erzielt werden kann, es können giftige und Verunreinigungen verursachende Säuren und Lösungsmittel vermieden werden und die Ätzung let wirtschaftlicher.Gas plasma etching is preferred over wet chemistry for several reasons. For example, the process is cleaner it can be simplified, improved resolution can be achieved, poisonous and impurities can be produced Causing acids and solvents are avoided and the etching is more economical.
Bisher war jedoch eine wirtschaftlich mögliche Ätzung von Aluminium mit üblichen Plasma-Ätzgasen nicht möglich, da Aluminiumoxid (Al2O,) auf frisch präparierten Aluminiumflächen, die der Atmosphärenluft ausgesetzt sind, eine Deckschicht bildet. Dieses Oxid schützt das darunterliegende Aluminium vor einem Ätzangriff durch die üblichen Ätzgase. Die vorliegende Erfindung ermöglicht das Gasätzen von Aluminium dadurch, daß zuerst in der Gegenwart eines gasförmigen Tri-Halogenids eine Plasma-Ätzung durchgeführt wird, vorzugsweise in einem sogenannten "Pfannkuchen-1* (pancake) oder Radialfluß-Reaktor, um die Oxidschicht zu entfernen. Dann kann das Ätzen des Aluminiums entweder mit oder ohne Plasmabedingungen fortgesetzt werden, je nachdem, welches Gas verwendet wird.Up to now, however, an economically feasible etching of aluminum with conventional plasma etching gases was not possible, since aluminum oxide (Al 2 O,) forms a cover layer on freshly prepared aluminum surfaces that are exposed to atmospheric air. This oxide protects the aluminum underneath from etching attack by the usual etching gases. The present invention enables the gas etching of aluminum by first plasma etching is performed in the presence of a gaseous tri-halide, preferably remove in a so-called "pancake 1 * (pancake) or radial flow reactor to the oxide layer. Etching of the aluminum can then proceed either with or without plasma conditions, depending on which gas is used.
Di· Erfindung wird nachfolgend anhand der Zeichnung beispielsweise nfther erläutert; in der Zeichnung zeigtt The invention is explained below with reference to the drawing, for example; in the drawing shows t
Fig. 1 «inen Querschnitt durch eine besondere ftruktur •ines Halbleitergerätes,Fig. 1 is a cross-section through a special structure • a semiconductor device,
Fig. 2 «in· schematlsche Darstellung einer Vorrichtung, bei der der Reaktor im Querschnitt gezeigt ist.Fig. 2 in a schematic representation of a device in which the reactor is shown in cross section.
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- if -- if -
Beim Plasma-Ätzen werden Ätzgasmoleküle in einem HF-Plasma in chemisch aktive Radikale aufgebrochen, die mit dem zu bearbeitenden Material reagieren. Es tritt ein Ätzvorgang auf und, wenn die erzeugten Reaktionsprodukte flüchtig sind, wird die Reaktion fortgesetzt, bis einer der beiden Reaktanten vollständig entfernt wird. Typische Reaktionstemperaturen sind 20 ° C<T<130 ° C und es wird mit vernünftigen Geschwindigkeiten geätzt, wenn der Dampfdruck der Reaktionsprodukte etwa gleich 0,1 Torr beträgt. Die Verbindungen AlBr^ und AlCl, besitzen Dampfdruckwerte von ~1 Torr bei 100 ° C, eö daß vom Standpunkt des Dampfdruckes aus Aluminium mit Ätzgasen, die Chlor oder Brom enthalten,ätzbar sein sollte. Es hat sich jedoch herausgestellt, daß das Aluminium nicht geätzt wird, auch nicht bei Temperaturen bis zu 300 ° C, wenn es mit Chlorgas (CIp) oder mit Chlorwasserstoff (HCl) versucht wurde. Das wird auf die Schutzwirkung einer dünnen ΑΙρΟ,-Schicht zurückgeführt. Diese Schicht wird von Cl2 oder HCl nicht gefitzt, da diese Ätzgase das Al2O, nicht reduzieren können.During plasma etching, etching gas molecules are broken up in an HF plasma into chemically active radicals, which react with the material to be processed. Etching occurs and, if the reaction products generated are volatile, the reaction continues until one of the two reactants is completely removed. Typical reaction temperatures are 20 ° C <T <130 ° C and etching is carried out at reasonable rates when the vapor pressure of the reaction products is approximately equal to 0.1 torr. The compounds AlBr ^ and AlCl, have vapor pressures of ~ 1 Torr at 100 ° C, so that, from the standpoint of vapor pressure, aluminum should be etchable with etching gases containing chlorine or bromine. However, it has been found that the aluminum is not etched, not even at temperatures up to 300 ° C, when attempted with chlorine gas (CIp) or with hydrogen chloride (HCl). This is attributed to the protective effect of a thin ΑΙρΟ, layer. This layer is not covered by Cl 2 or HCl, as these etching gases cannot reduce the Al 2 O.
Eine typische Struktur, wie sie bei der Herstellung von Halbleitergeräten geätzt werden muß, ist in Fig. 1 dargestellt. Eine Aluminiumschicht 10 (typischerweise 0,2 bis 1,0/an stark) bedeckt eine Schicht aus SiO2 oder Si-zN, 11, die über einem Substrat 12 aus Silizium liegt. Das zu fitzende Muster wird bestimmt durch die Photoresist-Schicht 13, so daß nur die durch das Photoresist nicht bedeckten Bereiche gefitzt werden. Es ist erforderlich, daß die Ätzung bis zur Trennfläche der Schichten 10 und 11 durchgeführt wird, ohne daß mehr als 0,1 /£m unter die Kante der Photoresist-Maske geätzt wird. Der Ätzangriff auf dit Schicht 11 muß so klein wie möglich sein und idealerweise sollte diese Schicht die Ätzung beenden, so daß die Aluminiumschicht 10 so lang geätzt werden kann, bis alle freigelegten Flächen weggeätzt sind, ohne einen merklichen Angriff auf die schicht 11. Die Entfernung des Aluminiumoxids von der" Ober-A typical structure such as must be etched in the manufacture of semiconductor devices is shown in FIG. An aluminum layer 10 (typically 0.2 to 1.0 / an thick) covers a layer of SiO 2 or Si-zN, 11, which lies over a substrate 12 of silicon. The pattern to be fitzten is determined by the photoresist layer 13, so that only the areas not covered by the photoresist are fetted. It is necessary that the etching be carried out to the interface of layers 10 and 11 without etching more than 0.1 / m below the edge of the photoresist mask. The etch attack on dit layer 11 must be as small as possible and ideally this layer should terminate the etching, so that the aluminum layer 10 can be etched so long until all exposed surfaces etched away without a significant attack on the layer 11. The distance of aluminum oxide from the "upper
809808/0619809808/0619
fläche des Aluminiums zum Anfang jedes ÄtzVorgangs ist ein Schlüsselvorgang für Plasmaätzprozesse beim Aluminium. Die dünne Aluminiumoxid schicht ist in Fig. 1 mit 1 if bezeichnet.area of the aluminum at the beginning of each etching process is a Key process for plasma etching processes on aluminum. The thin aluminum oxide layer is designated in Fig. 1 with 1 if.
Für das Ätzverfahren wird ein "Pfannkuchenform-Reaktor" (pancake style- reactor) verwendet, wie er in Fig. 2 dargestellt ist. Das Ätzgas wird in die Reaktionskammer 21 durch das Nadelventil 22 eingelassen und ein Druck P wird durch eine mechanische Vakuumpumpe 23 aufrechterhalten, die die Reaktionskammer 21 durch das Drosselventil 2h hindurch auspumpt. Die Durchflußrate wird durch Einstellen des Nadelventils 22 festgelegt und durch das Mengendurchfluß-Meßgerät 25 überwacht, während der Druck durch Einstellen des Drosselventils 24 festgelegt wird und durch das Druckmeßgerät 26 überwacht wird. Durchflußraten von 5 bis 500 cnr/min und Druckwerte von 0,25 bis 1,0 Torr sind für den Vorgang typisch. In dem Reaktor wird durch Anlegen einer Hochfrequenzleistung aus dem HF-Generator 27 an die Elektroden 28 und 29 erzeugt, die durch die zylindrische Reaktorwand 30 aus Quarz voneinander getrennt sind. Typischerweise werden Leistungswerte von 10 bis 500 W verwendet. Eine Impedanz-Abgleichschaltung in dem HF-Generator 27 dient zur Optimierung der Leistungszuführung in den Reaktor. Die zu bearbeitenden Teile 31 ruhen auf der Stützelektrode 32f die mittels einer elektrischen Beheizung und/oder einer umlaufenden Flüssigkeit temperaturgesteuert wird.A "pancake style reactor" as shown in FIG. 2 is used for the etching process. The etching gas is admitted into the reaction chamber 21 through the needle valve 22 , and a pressure P is maintained by a mechanical vacuum pump 23 which pumps out the reaction chamber 21 through the throttle valve 2h . The flow rate is determined by adjusting the needle valve 22 and monitored by the mass flow meter 25, while the pressure is determined by adjusting the throttle valve 24 and monitored by the pressure meter 26. Flow rates from 5 to 500 cnr / min and pressures from 0.25 to 1.0 torr are typical for the process. In the reactor, a high-frequency power is generated from the HF generator 27 to the electrodes 28 and 29, which are separated from one another by the cylindrical reactor wall 30 made of quartz. Typically, power values from 10 to 500 W are used. An impedance matching circuit in the HF generator 27 is used to optimize the power supply to the reactor. The parts 31 to be processed rest on the support electrode 32 f which is temperature-controlled by means of electrical heating and / or a circulating liquid.
51·· Ü*t«fl.ektroden 32 und die Elektrode 29 sind elektrisch miteinander verbunden und befinden sich normalerweise beide auf Erdpotential. Das Ätzgas fließt in Radialrichtung durch die Plasmaregion, wobei das Fließmuster zylindrische Symmetrie aufweist. Eine gleichartige Vorrichtung wurde bisher für die Plasmaablagerung von Si5N, nach der US-PS 3 757 733 verwendet. Zum Plasmaätzen wird die Elektrode 32 bei einer vorgewählten Temperatur von typischerweise 50 bis 1300C gehalten, die51 ·· Ü * t «fl. Electrodes 32 and the electrode 29 are electrically connected to one another and are normally both at ground potential. The etching gas flows in a radial direction through the plasma region, the flow pattern having cylindrical symmetry. A similar device has heretofore been used for the plasma deposition of Si 5 N, according to US Pat. No. 3,757,733. For plasma etching, the electrode 32 is kept at a preselected temperature of typically 50 to 130 0 C, the
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zu bearbeitenden Teile oder wafer 31 werden auf die durch die Elektrode gebildeten Platte abgeladen, die Elektrode wird aufgesetzt, der Reaktor evakuiert mit einer vorhergehenden Spülung mit Argon, das Ätzgas wird eingeleitet und beim Einschalten der HF-Leistung beginnt der Ätzvorgang. Der Ätzvorgang kann durch Augenschein überwacht werden.Parts to be processed or wafers 31 are unloaded onto the plate formed by the electrode, the electrode is placed, the reactor evacuated with a previous flushing with argon, the etching gas is introduced and the etching process begins when the HF power is switched on. The etching process can be monitored visually.
Die Elektroden sollten aus einem gegenüber dem Plasma inerten Leiter bestehen. Es kann nichtrostender Stahl verwendet werden, wenn auch ein geringfügiger Ätzangriff auf die Elektroden erfolgt und eine Vergiftung durch den relativ niederen Dampfdruck des Nickel, des Eisen, des Chroms und des Natriumchlorids sich auf den Werkstücken während des Ätzens ablagern kann. Diese Vergiftung kann für einige Zwecke zugelassen werden, jedoch wird bei Halbleitergeräten, besonders bei MOS-Qeräten eine solche Vergiftung die wafer unbrauchbar machen. Die Vergiftung kann vermieden werden, wenn Kohlenstoff-Elektroden verwendet werden. Ein weiteres Elektrodenmaterial ist Silizium-Carbid. The electrodes should consist of a conductor that is inert to the plasma. Stainless steel can be used, even if there is a slight etching attack on the electrodes and poisoning due to the relatively low vapor pressure nickel, iron, chromium and sodium chloride can deposit on the workpieces during etching. This poisoning can be allowed for some purposes, but it is used in semiconductor devices, especially MOS devices such poisoning will render the wafers unusable. Poisoning can be avoided if carbon electrodes be used. Another electrode material is silicon carbide.
In der verwendeten Reaktorart ändern sich das HF-Feld, das Plasma und der Ätzgasfluß in Radialrichtung, und damit die Anzahl der erzielbaren ÄtzvorgÄllge end die itegeeähwifidigkeit. Es ist bekannt, daß eine gleichförmige Ätzrate erreicht werden kann, indem Elektrodenabstand, HF-Leistung und die Durchflußrate des Ätzgases in richtiger Weise eingestellt werden. Eine weitere Begrenzung der Plasma-Parameter besteht darin, daß die HF-Leistung genügend klein sein muß, um die Photoresist-Maske nicht durch Ionenbeschuß zu beschädigen und daß die Wafer-Temperatur genügend niedrig G&13O ° C) bleiben sollte, um eine hohe Erosion der Photoresist-Maske und ein Vernetzen während des Ätzens zu vermeiden.In the type of reactor used, the HF field, the plasma and the flow of etching gas change in the radial direction, and thus the number of etching processes that can be achieved end the iteability. It is known that a uniform etching rate can be achieved by properly adjusting the electrode spacing, RF power, and the flow rate of the etching gas. Another limitation of the plasma parameters is that the RF power must be small enough so that the photoresist mask is not damaged by ion bombardment and that the wafer temperature should remain low enough to prevent high erosion Avoid photoresist mask and cross-linking during etching.
Ein geeignetes Ätzgas zum Ätzen von Aluminium sollte ein solches Radikal in dem Plasma bilden, da#-A suitable etching gas for etching aluminum should form such a radical in the plasma that # -
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1) die Schutzschicht aus Al2O, entfernt am ein1) the protective layer of Al 2 O, removed on a
Ätzen des darunterliegenden Aluminiums zu ermöglichen,To enable etching of the underlying aluminum,
2) ein Aluminiumätz-Radikal wie Cl in dem Plasma [ fciliet, · das ein flüchtiges Reaktionsprodukt ergibt,2) an aluminum etching radical such as Cl in the plasma [ fciliet, which gives a volatile reaction product,
3) das darunterliegende Substrat nicht wesentlich angreift, ff) die Photoreslst-Ätzmaske nicht wesentlich erodiert,3) does not significantly attack the underlying substrate, ff) does not significantly erode the photoresist etch mask,
5) die Bestandteile des Reaktors oder der Vakuumpumpe nicht wesentlich angreift, und5) does not significantly attack the components of the reactor or the vacuum pump, and
6) keine Polymere oder andere Ablagerungen oder Reststoffe bildet.6) does not form polymers or other deposits or residues.
Diese Forderungen werden durch BCl, oder durch Gemische aus BCl,, Cl2 und inerten Gasen erfüllt. Die Auswahl von BCl, beruht auf der Hypothese, daß dieses sich im Plasma in BCl2- und Cl-Radikale zersetzt, wobei das BCIp ein stark reduzierendes Mittel für Al2O, darstellt, das wahrscheinlich über ein flüchtiges Oxidchlorid wirkt und das Cl für die Ätzung von Al über ein flüchtiges AlCl, wirkt. Eine gleichmäßige Ätzung von Aluminiumlinien von 2/un in 6000 Ä starkem Aluminium kann regelmäßig erreicht werden, wenn bei 800C etwa 20 Minuten lang mit einem BCl,-Druck von 0,5 Torr bei 50 W in einem Reaktor mit einem Durchmesser von 30Jf,8 mm (= 12") geätzt wird. Dae Al2Oz wird schnell entfernt (< 2 Minuten) und die Ätzrate des Aluminiums wird dann durch die Anzahl der Radikale begrenzt, die für die Aluminiumätzung zur Verfügung stehen. Eine Hinzufügung von geringen Mengen von Cl2 zum Ätzgas nach zwei Minuten der Ätzung mit BCl, ergibt eine Verkürzung der für die Aluminiumentfernung erforderlichen Gesamtzeit, und auf diese Weise können sehr große Ätzraten erreicht werden.These requirements are met by BCl, or by mixtures of BCl ,, Cl 2 and inert gases. The choice of BCl is based on the hypothesis that this decomposes in the plasma into BCl 2 - and Cl radicals, the BCIp being a strongly reducing agent for Al 2 O, which probably acts via a volatile oxide chloride and Cl for the etching of Al via a volatile AlCl is effective. A uniform etching of aluminum lines of 2 / un in 6000 Å thick aluminum can regularly be achieved if at 80 0 C for about 20 minutes with a BCl, pressure of 0.5 Torr at 50 W in a reactor with a diameter of 30 Jf .8 mm (= 12 ") is etched. Dae Al 2 Oz is removed quickly (< 2 minutes) and the etch rate of the aluminum is then limited by the number of radicals available for the aluminum etch. An addition of small amounts from Cl 2 to the etching gas after two minutes of etching with BCl, results in a reduction in the total time required for aluminum removal and in this way very high etch rates can be achieved.
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Es ist eine Eigenschaft der vorliegenden Erfindung, daß nach Entfernung der Al-O^-Schicht 1/f durch Plasmaätzung die Aluminiumschicht 10 durch Chlor ohne HF-Anregung, d.h. ohne Plasmabedingungen geätzt werden kann. Es hat sich herausgestellt, daß die Ätzrate unter solchen Bedingungen extrem hoch ist. Eine Vermischung des Chlorgases mit einem inerten Gas, beispielsweise Argon, ergibt steuerbare Ätzraten.It is a feature of the present invention that after Removal of the Al-O ^ layer 1 / f by plasma etching the aluminum layer 10 by chlorine without HF excitation, i.e. without plasma conditions can be etched. It has been found that the etching rate is extremely high under such conditions. One Mixing the chlorine gas with an inert gas, for example argon, results in controllable etching rates.
Das plasmalose Ätzen der Aluminiumschicht 10 ist vom Standpunkt der Beschädigung der Silizium-Bauteile aus möglicherweise wünschenswert, da das Plasma nur für die Entfernung der Al-O,-Schicht erforderlich ist, und während dieser Zeit ist das Gerät vor Strahlung durch die Aluminiumschicht 10 geschützt. Es besteht sehr geringe Wahrscheinlichkeit, daß das Bauteil beschädigt wird, wenn das Aluminium unter Nicht-Plasmabedingungen durchgeätzt wird. Ein zusätzlicher Vorteil besteht darin, daß eine sehr geringe Beschädigung der unterliegenden SiOp-Schicht 11 während des Ätzens, die mit BCl, bei hoher Leistungseingabe auftreten kann, in der plasmalosen Ätzbedingung nicht auftritt und auch nicht, wenn ein Gemisch aus Chlorgas und inertem Gas bei Plasmaätzung benutzt wird.The plasma-free etching of the aluminum layer 10 may be desirable from the standpoint of damaging the silicon components, because the plasma is only used to remove the Al-O, layer is required, and during this time the device is protected from radiation by the aluminum layer 10. There is very little chance that the component will be damaged if the aluminum is in non-plasma conditions is etched through. An additional advantage is that there is very little damage to the underlying SiOp layer 11 during etching that with BCl, with high power input can occur in the plasma-less etching condition and also not when a mixture of chlorine gas and inert gas is used for plasma etching.
Es können auch andere Gase bei dem Plasmaätzvorgang benutzt werden, beispielsweise BBr^. Allgemein sind Bor-Tri-Halogenide zum Plasmaätzen zur Entfernung der Aluminiumoxidechicht geeignet. Chlorgas oder ein Gemisch aus Chlor- und einem inerten Gas wird, wenn nötig, zugegeben, um das Ätzen des Aluminiums nach dem Entfernen des Aluminium-Oxides unter Plasmabedingungen oder plasmalosen Bedingungen zu ermöglichen. Der Durchfluß von Bor-Tri-Halogeniden kann beendigt werden, wenn plasmaloses Ätzen mit Chlorgas ausgeführt wird.Other gases can also be used in the plasma etching process, for example BBr ^. Common are boron tri-halides suitable for plasma etching to remove the aluminum oxide layer. Chlorine gas or a mixture of chlorine and an inert gas is added if necessary to post-etch the aluminum to enable the aluminum oxide to be removed under plasma or plasma-less conditions. The flow of boron tri-halides can be terminated when plasma-less etching with chlorine gas is performed.
Es ist also gezeigt, daß Gasplasmaätzen von Aluminium mit konventionellen Plasmaätzgasen bisher nicht kommerziell möglichIt has thus been shown that gas plasma etching of aluminum with conventional plasma etching gases has not been commercially possible up to now
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war, da sich auf frisch präparierten Aluminiumflächen eine Schicht von Aluminiumoxid (Al-O^) bildet. Dadurch, daß zuerst eine Plasmaätzung in Gegenwart von gasförmigem Tri-Halogenid stattfindet und zwar vorzugsweise in einem sogenannten "Pfannkuchen11- oder Radialfluß-Reaktor, wird die Oxidschicht entfernt. Das Aluminium wird dann weiterhin geätzt, entweder unter Plasmabedingungen oder ohne solche, je nachdem, welches Ätzgas verwendet wird.because a layer of aluminum oxide (Al-O ^) forms on freshly prepared aluminum surfaces. By first plasma etching in the presence of gaseous tri-halide, preferably in a so-called "pancake 11 " or radial flow reactor, the oxide layer is removed. The aluminum is then further etched, either under or without plasma conditions, as the case may be which etching gas is used.
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Claims (1)
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CA259,126A CA1059882A (en) | 1976-08-16 | 1976-08-16 | Gaseous plasma etching of aluminum and aluminum oxide |
Publications (2)
Publication Number | Publication Date |
---|---|
DE2730156A1 true DE2730156A1 (en) | 1978-02-23 |
DE2730156C2 DE2730156C2 (en) | 1986-01-16 |
Family
ID=4106655
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
DE2730156A Expired DE2730156C2 (en) | 1976-08-16 | 1977-07-04 | Gas plasma etching of aluminum and aluminum oxide |
Country Status (7)
Country | Link |
---|---|
JP (1) | JPS5322836A (en) |
CA (1) | CA1059882A (en) |
DE (1) | DE2730156C2 (en) |
FR (1) | FR2362216A1 (en) |
GB (1) | GB1554335A (en) |
NL (1) | NL7706627A (en) |
SE (1) | SE7709165L (en) |
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE2930291A1 (en) * | 1978-07-31 | 1980-02-21 | Western Electric Co | METHOD FOR PRODUCING AN OBJECT USING PLASMA ETCHING |
DE2930292A1 (en) * | 1978-07-31 | 1980-02-28 | Western Electric Co | ACTION PROCESS IN PRODUCING AN OBJECT |
DE2930290A1 (en) * | 1978-07-31 | 1980-02-28 | Western Electric Co | METHOD FOR PRODUCING AN OBJECT |
DE2924475A1 (en) * | 1979-06-18 | 1981-01-15 | Siemens Ag | Metallising of semiconductor crystals - where semiconductor is covered with metal and then with metal oxide which aids the adhesion of photolacquer masks |
DE3029124A1 (en) * | 1979-08-01 | 1981-02-05 | Hitachi Ltd | PLASMAAETZER |
DE3030814A1 (en) * | 1979-08-17 | 1981-02-26 | Tokuda Seisakusho | PLASMA METHOD |
EP0047002A2 (en) * | 1980-09-03 | 1982-03-10 | Kabushiki Kaisha Toshiba | Plasma etching apparatus |
DE3103177A1 (en) * | 1981-01-30 | 1982-08-26 | Siemens AG, 1000 Berlin und 8000 München | METHOD FOR PRODUCING POLYSILIZIUM STRUCTURES UP TO THE 1 (MY) M AREA ON SUBSTRATES CONTAINING INTEGRATED SEMICONDUCTOR CIRCUITS BY PLASMA |
Families Citing this family (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS54118172A (en) * | 1978-03-06 | 1979-09-13 | Nichiden Varian Kk | Method of dry etching aluminum |
US4426246A (en) * | 1982-07-26 | 1984-01-17 | Bell Telephone Laboratories, Incorporated | Plasma pretreatment with BCl3 to remove passivation formed by fluorine-etch |
JP2861785B2 (en) * | 1994-02-15 | 1999-02-24 | 日本電気株式会社 | Method for forming wiring of semiconductor device |
US9520303B2 (en) * | 2013-11-12 | 2016-12-13 | Applied Materials, Inc. | Aluminum selective etch |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3615956A (en) * | 1969-03-27 | 1971-10-26 | Signetics Corp | Gas plasma vapor etching process |
US3757733A (en) * | 1971-10-27 | 1973-09-11 | Texas Instruments Inc | Radial flow reactor |
-
1976
- 1976-08-16 CA CA259,126A patent/CA1059882A/en not_active Expired
-
1977
- 1977-06-13 GB GB24546/77A patent/GB1554335A/en not_active Expired
- 1977-06-16 NL NL7706627A patent/NL7706627A/en not_active Application Discontinuation
- 1977-07-04 DE DE2730156A patent/DE2730156C2/en not_active Expired
- 1977-08-02 JP JP9230477A patent/JPS5322836A/en active Granted
- 1977-08-12 SE SE7709165A patent/SE7709165L/en unknown
- 1977-08-16 FR FR7725071A patent/FR2362216A1/en not_active Withdrawn
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3615956A (en) * | 1969-03-27 | 1971-10-26 | Signetics Corp | Gas plasma vapor etching process |
US3757733A (en) * | 1971-10-27 | 1973-09-11 | Texas Instruments Inc | Radial flow reactor |
Cited By (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE2930291A1 (en) * | 1978-07-31 | 1980-02-21 | Western Electric Co | METHOD FOR PRODUCING AN OBJECT USING PLASMA ETCHING |
DE2930292A1 (en) * | 1978-07-31 | 1980-02-28 | Western Electric Co | ACTION PROCESS IN PRODUCING AN OBJECT |
DE2930290A1 (en) * | 1978-07-31 | 1980-02-28 | Western Electric Co | METHOD FOR PRODUCING AN OBJECT |
DE2924475A1 (en) * | 1979-06-18 | 1981-01-15 | Siemens Ag | Metallising of semiconductor crystals - where semiconductor is covered with metal and then with metal oxide which aids the adhesion of photolacquer masks |
DE3029124A1 (en) * | 1979-08-01 | 1981-02-05 | Hitachi Ltd | PLASMAAETZER |
DE3030814A1 (en) * | 1979-08-17 | 1981-02-26 | Tokuda Seisakusho | PLASMA METHOD |
EP0047002A2 (en) * | 1980-09-03 | 1982-03-10 | Kabushiki Kaisha Toshiba | Plasma etching apparatus |
EP0047002A3 (en) * | 1980-09-03 | 1982-03-24 | Tokyo Shibaura Denki Kabushiki Kaisha | Plasma etching apparatus |
DE3103177A1 (en) * | 1981-01-30 | 1982-08-26 | Siemens AG, 1000 Berlin und 8000 München | METHOD FOR PRODUCING POLYSILIZIUM STRUCTURES UP TO THE 1 (MY) M AREA ON SUBSTRATES CONTAINING INTEGRATED SEMICONDUCTOR CIRCUITS BY PLASMA |
Also Published As
Publication number | Publication date |
---|---|
FR2362216A1 (en) | 1978-03-17 |
GB1554335A (en) | 1979-10-17 |
CA1059882A (en) | 1979-08-07 |
SE7709165L (en) | 1978-02-17 |
NL7706627A (en) | 1978-02-20 |
DE2730156C2 (en) | 1986-01-16 |
JPS5322836A (en) | 1978-03-02 |
JPS5745310B2 (en) | 1982-09-27 |
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