Remote Arc Discharge Plasma Assisted Processes

Abstract

A coating system includes a vacuum chamber and a coating assembly. The coating assembly has a coating assembly which includes a vapor source, a substrate holder to hold substrates to be coated such that the substrates are positioned in front of the vapor source, a primary cathodic vacuum-arc assembly, a remote anode electrically coupled to the cathode target, a primary power supply connected between the cathode target and the primary anode, and a secondary power supply connected between the cathode target and the remote anode. The primary cathodic vacuum-arc assembly includes a cathode chamber assembly, a cathode target, an optional primary anode and a shield which isolates the cathode target from the vacuum chamber. The shield defines openings for transmitting either electron emission current or metal vapor plasma from the cathode target into the vacuum chamber. The vapor source is positioned between the cathode chamber assembly and the remote anode.

What is claimed is: 
     
         1 . A coating system comprising:
 a vacuum chamber; and   a coating assembly positioned in the vacuum chamber, the coating assembly including:
 a vapor source; 
 a substrate holder to hold substrates to be coated such that the substrates are positioned in front of the vapor source; 
 a primary cathodic vacuum-arc assembly including a cathode chamber assembly, a cathode target, an optional primary anode and a shield which isolates the cathode target from the vacuum chamber, the shield defining openings for transmitting either electron emission current or metal vapor plasma from the cathode target into the vacuum chamber; 
 a remote anode electrically coupled to the cathode target; 
 a primary power supply connected between the cathode target and the primary anode; and 
 a secondary power supply connected between the cathode target and the remote anode, the vapor source being positioned between the cathode chamber assembly and the remote anode, the remote anode having a linear remote anode dimension, the vapor source having a linear vapor source dimension, the cathode target having a linear cathode target dimension, and the substrate holder having a linear holder dimension such that the linear remote anode dimension, the linear vapor source dimension, and the linear holder dimension are parallel to each other, with the linear remote anode dimension being equal to or greater than the linear vapor source dimension such that a confined plasma streams from the cathode target to the remote anode. 
   
     
     
         2 . The system of  claim 1  wherein the linear vapor source dimension is a long side that is parallel to linear cathode target dimension, the linear vapor source dimension being parallel to the linear cathode target dimension. 
     
     
         3 . The system of  claim 1  wherein the linear vapor source dimension is a short side that is parallel to linear cathode target dimension. 
     
     
         4 . The system of  claim 1  wherein the primary anode is a ground or the shield. 
     
     
         5 . The system of  claim 1  further comprising at least one additional vapor source positioned between the cathode chamber assembly and the remote anode. 
     
     
         6 . The system of  claim 5  wherein perpendicular distances between each of the vapor sources and the substrates to be coated are substantially equal and the distance between the cathode chamber assembly and the remote anode is less than the distance at which breakdown occurs when an applied voltage of the secondary power supply exceeds 1.2 to 10 times the applied voltage of the primary power supply. 
     
     
         7 . The system of  claim 5  wherein a plurality of cathode targets are coupled to the remote anode, each cathode target of the plurality of cathode targets having a linear cathode target dimension that is parallel to the linear remote anode dimension. 
     
     
         8 . The system of  claim 1  wherein a separation from the top of the cathode chamber assembly to substrates is from about 2 to 20 inches. 
     
     
         9 . The system of  claim 1  wherein an external magnetic field is applied along a region between the vapor source and the substrates to be coated. 
     
     
         10 . The system of  claim 9  wherein the external magnetic field is applied to magnetically insulate the cathode target of the cathode chamber assembly. 
     
     
         11 . The system of  claim 9  wherein the external magnetic field is applied to magnetically insulate the anode of the remote anode. 
     
     
         12 . The system of  claim 1  wherein the vapor source comprises a component selected from the group consisting of a magnetron, a thermal evaporator, an electron beam evaporator, and a cathodic arc evaporator. 
     
     
         13 . The system of  claim 1  wherein the cathode target comprises a component selected from the group consisting of a cold vacuum arc cathode, a hollow cathode, a thermionic filament cathode, an electron beam evaporator, and combinations thereof. 
     
     
         14 . The system of  claim 11  wherein the cathode target is made of metal having a gettering capability including titanium and zirconium alloys. 
     
     
         15 . The system of  claim 1  wherein the shield of the cathode chamber is water cooled and negatively biased in relation to the cathode target wherein a bias potential of the shield ranges from −50 volts to −1000 volts 
     
     
         16 . The system of  claim 1  wherein plasma probes are installed between the cathode chamber assembly and the remote anode to measure plasma density, the plasma probes providing feedback for controlling the secondary power supply in which a remote anode current is adjusted to obtain a uniform distribution of the plasma density between the cathode chamber assembly and the remote anode. 
     
     
         17 . The system of  claim 1  wherein the cathode target is part of a cathode array having a plurality of cathode targets installed in the cathode chamber assembly, a linear dimension of each cathode target being substantially equal to the linear dimension of the remote anode. 
     
     
         18 . The system of  claim 1  wherein the cathode target is a plate or a bar. 
     
     
         19 . The system of  claim 1  wherein a plurality of slave remote anodes are connected to the remote anode via variable resistors. 
     
     
         20 . The system of  claim 19  wherein a plurality of slave remote anodes are connected to the remote anode with capacitors. 
     
     
         21 . The system of  claim 1  comprising a plurality of coating assemblies. 
     
     
         22 . The system of  claim 21  wherein the plurality of coating assemblies is aligned essentially inline. 
     
     
         23 . The system of  claim 1  wherein the vapor source, the cathode target and the remote anode are distributed along a linear direction with the substrate holder moving along the linear direction. 
     
     
         24 . The system of  claim 1  wherein the vacuum chamber has a circular cross section with the cathode target and the remote anode distributed about a central axis of the vacuum chamber with the substrate holder moving in a circular direction. 
     
     
         25 . The system of  claim 1  wherein the primary cathodic vacuum-arc assembly includes a filtered cathodic vacuum-arc source. 
     
     
         26 . The system of  claim 25  wherein the filtered cathodic vacuum-arc source includes a cathode target and a plasma duct, the plasma duct having a long side, the plasma duct having a bend section along a centerline of the plasma duct, the plasma duct having a cathode chamber portion and an exit tunnel portion on opposite sides of the bend. 
     
     
         27 . The system of  claim 26  wherein the plasma duct has a rectangular cross-sectional shape of similar dimensions to the cathode target. 
     
     
         28 . The system of  claim 26  wherein the cathode chamber assembly includes a rectangular tube. 
     
     
         29 . The system of  claim 26  wherein the cathode target is mounted on an isolated holder at an end of cathode chamber portion so that an evaporable surface of the cathode target faces into the plasma duct. 
     
     
         30 . The system of  claim 26  wherein the bend has an angle from about 60 to 120 degrees. 
     
     
         31 . The system of  claim 26  further including a magnetic shutter having deflecting magnets and focusing electromagnets disposed about the plasma duct, the deflecting magnets positioned about an outer side of the cathode chamber and the bend section, the focusing electromagnetics positioned at the exit of the plasma duct. 
     
     
         32 . The system of  claim 31  wherein the magnetic shutter is open when both deflection electromagnets and the focusing electromagnets are activated such that ionized filtered metal vapor plasma generated at the cathode target are transported through the plasma duct toward substrates. 
     
     
         33 . The system of  claim 31  wherein a gaseous environment is also highly ionized within a narrow corridor defined between the substrates and walls of the vacuum chamber along a remote arc discharge path. 
     
     
         34 . The system of  claim 31  wherein the vapor sources includes a plurality of magnetron sputtering source that combines discharge with a remote anode arc discharge thereby allowing an increase ionization of the magnetron sputtering source. 
     
     
         35 . The system of  claim 31  wherein the magnetic shutter is closed when the deflecting magnets and the focusing electromagnets are not activated such that metal vapor plasma generated by the cathode target is trapped within the plasma duct while a remote anode arc discharge runs between the cathode target and the remote anode providing ionization and activation of coating deposition environment along a corridor defined between the substrates and walls of the vacuum chamber. 
     
     
         36 . The system of  claim 31  wherein a plurality of magnetron sputtering sources and remote anodes are positioned on a hub in a central region of the vacuum chamber such that a remote arc discharge fill a region between the hub and walls of the vacuum chamber. 
     
     
         37 . The system of  claim 31  wherein the vapor source include a bi-directional filtered arc source having a bi-directional plasma duct the remote anodes installed at a peripheral rim of the bi-directional plasma duct, a remote anode arc discharge being established along a corridor defined between an outer rim of the plasma duct and the substrates. 
     
     
         38 . The system of  claim 37  wherein the bi-directional plasma duct further includes shields at both ends of the bi-directional plasma duct. 
     
     
         39 . The system of  claim 37  wherein the remote anode arc discharge is supported either by a unidirectional filtered vacuum-arc source and/or by the bi-directional filtered arc source, such that a remote anode arc discharge plasma fills a coating deposition area defined between an outer wall of the bi-directional filtered arc source and walls of the vacuum chamber. 
     
     
         40 . The system of  claim 39  wherein the bi-directional filtered arc source and the unidirectional filtered arc source are configured to operate concurrently and independently in a magnetic shutter mode while coupled with magnetron sputtering sources. 
     
     
         41 . The system of  claim 39  further comprising a first additional magnetron source and a second additional magnetron source positioned adjacent to the exit of the plasma duct in the vacuum chamber facing the substrates such that the magnetron sputtering flow is merging with the cathode target of the filtered arc source. 
     
     
         42 . The system of  claim 39  further comprising two magnetron sources positioned at the exit of the plasma duct. 
     
     
         43 . The system of  claim 31  configured to operate in an inline mode. 
     
     
         44 . The system of  claim 1  configured to operate in a batch mode. 
     
     
         45 . A coating system comprising:
 a coating chamber;   a vapor source having a target face with a vapor source long dimension and a vapor face short dimension;   a substrate holder to hold substrates to be coated such that the substrates are positioned within the coating chamber and in front of the vapor source, the substrate holder having a linear holder dimension;   a dual filtered arc unidirectional rectangular plasma source operating as a metal vapor plasma coating deposition source and an electron emitting source, the unidirectional dual filtered arc source including a rectangular plasma duct having deflecting section and an exit tunnel section, a first cathodic arc chamber having a first cathode target, a second cathodic arc chamber having a second cathode target, and a baffled anode plate, the first cathodic arc chamber and the second cathodic arc chamber separated by the baffled anode plate and positioned on opposite sides of a deflecting section;   a remote anode electrically coupled to the first cathode target and the second cathode target, the remote anode having a linear remote anode dimension, the vapor source having a linear vapor source dimension;   a primary power supply connected between the cathode target and a primary anode; and   a secondary power supply connected between the cathode target and the remote anode.   
     
     
         46 . The coating system of  claim 45  further comprising deflecting coils surrounding a deflection portion of the plasma duct. 
     
     
         47 . The coating system of  claim 45  further comprising stabilizing coils that surround the cathode chambers and confine confining cathodic arc spots at evaporable surface of the cathode targets. 
     
     
         48 . The coating system of  claim 45  further comprising focusing coils surrounding an exit portion of the cathode chambers that focus a metal vapor plasma stream towards a deflection portion of the plasma duct. 
     
     
         49 . The coating system of  claim 45  further comprising a first magnetron source and a second magnetron source positioned as an exit tunnel portion of the plasma duct, the first magnetron source and the second magnet source regulating the degree of ion bombardment by metal ions during a hybrid filtered arc enhanced magnetron sputtering coating deposition process. 
     
     
         50 . The coating system of  claim 45  further comprising a shielded cathodic arc electron emission source located centrally in the coating chamber. 
     
     
         51 . The system of  claim 45  configured to operate in an inline mode. 
     
     
         52 . The system of  claim 45  configured to operate in a batch mode.