KR20170059104A - Electro-chemical deposition system and method of electroplating on substrates - Google Patents

Abstract

SUMMARY OF THE INVENTION The present invention provides an apparatus and method for obtaining a reliable, constant metal electroplating or electrochemical deposition on a substrate. In particular, the present invention provides deposition of a uniform, void-free metal with a substrate having a submicron shape formed thereon and a metal seed layer formed thereon. The present invention provides an electrochemical deposition shell comprising a substrate holder, a cathode for electrically contacting the substrate plated surface, an electrolyte inlet adapted to receive the substrate, an electrolyte vessel having an electrolyte outlet and a number of cells, and an anode electrically connecting to the electrolyte .
Preferably, an auxiliary electrode is disposed adjacent the electrolyte outlet to provide uniform lamination across the substrate surface, attached to the substrate holder to vibrate the substrate in at least one direction. Preferably, the periodic reverse current is applied during the plate-shaped period to provide a non-poled metal layer in the aspect ratio feature on the substrate.

Description

[0001] ELECTROCHEMICAL DEPOSITION SYSTEM AND METHOD OF ELECTROPLATING ON SUBSTRATES [0002]

This application is related to U.S. Application No. 60 / 082,521, filed on April 21, 1998, entitled " Electroplating Stacking System and Method on a Board ".

The present invention relates to depositing a metal layer on a substrate. More particularly, the present invention relates to a method and apparatus for electroplating a metal layer on a substrate.

Sub-micron multi-level metallization is one of the key technologies for the next generation of ultralarge scale integration (ULSI). Multilevel is a key technology for including planarization of interconnect features in holes with high aspect ratios, including contacts, vias, lines and other features . The reliable formation of these interrelated features is critical to the succession of ULSI and requires continued efforts to increase circuit density and quality on each substrate and die.

When the circuit density is increased, the dielectric material between them in addition to the contact, the width of the via, and other features will reduce the sub-micron dimensions, while the thickness of the dielectric layer will remain constant, resulting in an aspect ratio to the feature, The height divided by the width is increased. Many conventional deposition methods are difficult to fill sub-micron structures when the aspect ratio exceeds 2: 1, especially when the aspect ratio exceeds 4: 1. Therefore, sub-micron features with aspect ratios have a great influence on the formation of non-pores. One element, aluminum (Al) and aluminum alloys, have low electrical resistance to aluminum, good adhesion to silicon dioxide (SiO2) Due to its ease of pattern formation and its ability to be obtained in high pure form, it has conventional metals used to form lines and plugs in semiconductor processes. However, aluminum has a greater electrical resistance than other conductive metals such as copper and silver, and is not good for electromigration phenomena. Electromigration can be achieved by atomic transfer of metal conductors in response to high current density passages.

Is a phenomenon occurring in a metal circuit during operation of the circuit, not an error occurring during manufacture. Electromigration can also lead to the formation of voids in conductors. The pores may accumulate in an insufficient size to support the amount of current through the conductor, and may cause an open circuit. Thus, the conductor area that can utilize thermal conduction reduces the formation of voids and increases the risk of conductor damage. This problem is sometimes overcome by doping aluminum with copper and airtight fibers or by controlling the crystal structure of the material. However, electromigration in aluminum increases with increasing current density.

Copper and copper alloys have lower resistivity and higher electromigration resistance than aluminum. These features are obtained at high levels of integration and are important for supporting high current densities that increase device speed. In addition, copper has good thermal conductivity and is available in high pure state. Therefore, copper becomes a selection metal to fill sub-micron, aspect ratio related features on a semiconductor substrate.

Despite the use of copper for the fabrication of semiconductor devices, the choice of fabrication methods with high aspect ratio characteristics by stacking copper is limited. CVD lamination of copper is badly developed and involves complicated and expensive chemicals. Physical vapor deposition, which is dissatisfied with this product, is called "step coverage"

Due to the voids formed in the limits and features in the. As a limitation of such a process, electroplating, which is limited in advance to manufacture a pattern on a circuit board,

Lt; RTI ID = 0.0 > and / or < / RTI > contacts.

Generally, a barrier layer is formed over the surface of the features by physical vapor deposition, physical vapor deposition of a conductive metal seed layer, preferably vapor deposition of copper over the barrier layer, and deposition of an inductive material over the seed layer to fill the structure / And then electroplating. Finally, the stacked layers and dielectric layers are plated by chemical mechanical polishing (CMP) to form a conductive interconnect feature.

The cross-sectional diagram of the layered structure comprises a dielectric layer formed over the underlying layer comprising electrically conductive features. The lower layer comprises a doped silicon substrate

Or it may be a first or a continuous conductive layer formed on a substrate. The dielectric layer is formed on the underlying layer following procedures known in the art, such as dielectric CVD, to form part of the overall integrated circuit. After lamination, the dielectric layer is patterned, forming double damascene via and wire confinement

Lt; / RTI > The vias have a bottom exposed to the small portion of the conductive feature (15). Etching of the dielectric layer may be accomplished according to a generally well known dielectric etch process including plasma etch.

A cross-sectional view of a double damascene via formed in a dielectric layer and a wire shape is shown

All. The via and wire features facilitate lamination of the conductive interconnects, which provide electrical connection to the underlying conductive features. The shape provides a trench having a trench wall, a bottom exposed to at least a portion of the conductive feature, and a via having a via wall.

The barrier layer of tantalum or titanium nitride (TaN)

The holes are left in the vias by sputtering tantalum targets in, for example, a nitrogen / argon plasma, using reactive physical vapor deposition. Preferably, the aspect ratio of the holes is high (e. G., Greater than 4: 1) with sub-micron wide vias and Ta / TaN is deposited in a high density plasma environment. The sputtered stack of Ta / TaN is ionized and pulled at right angles to the substrate by the negative vias on the substrate. The barrier layer is preferably formed of tantalum or tantalum nitride, but other barrier layers such as titanium, titanium nitride and mixtures thereof may also be used. The process used may be PVD, CVD, or a combination of CVD / PVD to improve substrate and film properties. The barrier layer defines the dispersion of copper into the semiconductor substrate and dielectric layer, thus dramatically increasing the reliability of the interconnections. It is preferred that the barrier layer has a thickness of about 25 ANGSTROM to 400 ANGSTROM, preferably 100 ANGSTROM.

The PVD copper seed layer is disposed over the barrier layer. Other metals, especially precious metals,

Used for layers. The PVD copper seed layer is provided with good adhesion for metal layers that are continuously deposited and provides a conformal layer for the growth of copper.

The copper layer is electroplated over the PVD copper seed layer to fully fill the via with a copper plug.

The top of the structure, for example exposed copper, is removed by chemical mechanical polishing (CMP)

The substrate is shaped. During the plating process, portions of the copper seed layer, the barrier layer, the dielectric layer and the copper layer are removed from the upper surface of the structure, leaving a whole plate-like surface with conductive interconnections.

Metal electroplating is generally well known in the art and can be accomplished by a variety of techniques. A common design of the cell for electroplating metal on a wafer-based substrate involves a base shape. The substrate is placed on the plate shaped surface at a distance fixed on the cylindrical electrolyte container and the electrolyte impinges at a right angle on the substrate plate shaped surface. Since the substrate is composed of the cathode of the plate-like system, ions in the plate-

Are deposited on the surface of the conductive nurses and form micro-sites on the substrate. However, many obstacles

This sub-micron scale, high aspect ratio feature, causes copper to electroplating on a substrate, causing the substrate to break. In general, the three impediments are difficult to provide a uniform current density distribution across the substrate plate shaped surface. Such a plate-like surface is necessary for forming a metal layer having a uniform thickness. The first obstacle is how to provide current to the substrate and how to distribute the current evenly.

The current method for providing power to the substrate plate shaped surface uses contacts (e.g., pins, fingers, or springs) that contact the substrate seed layer. The contacts bring the seed layer into contact as close as possible to the edge of the substrate to minimize the area to be removed on the wafer due to the presence of the contacts. The " excluded " region is no longer used to ultimately form a device on a substrate. However, the contact resistance of the contact to the seed layer varies from the contact-to-contact and causes a non-uniform distribution of the current density across the substrate. Also, the contact resistance at the contacts to the seed layer interface varies from the contact-to-contact, resulting in an inconsistent plate-shaped distribution between other substrates using the same equipment. Moreover, the plate-like ratio becomes high near the area of contact due to the resistivity of the thin seed layer deposited on the substrate, and becomes low at the area far from the contact. The fringe effect in the electric field occurs at the edge of the substrate due to the high localized field generated at the edge of the plate-shaped area, which causes a high deposition rate near the edge of the substrate.

The resistive substrate effect appears during the early stages of the electroplating process and reduces the uniformity of the stack because the electroplating and seed layers on the substrate stacking surface are typically thin. The metal plate shape tends to be concentrated adjacent to the current supply contacts, e.g., the plate shape ratio is greatest near the contacts. This is because the current density across the substrate is reduced when the distance from the current supply glut is increased due to insufficient conduction material on the seed layer to provide a uniform current density across the substrate plate shape surface. Because a sufficient thickness of the deposited material can be used across the substrate plate shape surface to provide a uniform current density across the substrate when the lamination film thickness becomes thick due to the plate shape,

Is reduced.

The traditional base plate provides a non-uniform flow of debris across the surface of the substrate plate shape, which results in a non-uniform current distribution effect on the plate surface due to the non-uniform replenishment of plate ions, The gill plate additive causes a non-uniform plate shape. The electrolyte flow uniformity of the substrate can be improved by rotating the substrate at high speed during the plating process. This rotation complicates the plating shell design because it needs to supply current and rotate the interface. However, the plating uniformity is still potentially affected by the variable contact resistance

Is bad at the interface or edge of the substrate due to the seed layer resistance and the fringing effect of the electric field near the edge of the substrate.

In addition, there is a problem that the electroplating solution must be maintained in a system having a certain property during the plating cycle and / or during the execution of the multi-wafer to be plated. Traditionally, basic plasma designs typically require continuously refilling metals that are deposited with an electrolyte. The metal electrolyte recharge scheme is difficult to control and causes the accumulation of co-ions in the electrolyte, and consequently it is difficult to control the change in ion concentration in the electrolyte. Therefore, the electrolytic plating process produces uneven results due to the irregular ion concentration in the electrolyte.

Additionally, the operation of the plating shell using the non-consumable anode can cause problems with bubbles as oxygen is deployed on the anode during the electroplating process. Problems associated with bubbles include plating defects caused by bubbles reaching the substrate plating surface and preventing proper electrolyte contact with the plating surface. It is desirable to remove or reduce bubble formation from the system and remove the forming bubble from the system.

Therefore, there is a need for a reliable and consistent metal electroplating apparatus and method for depositing uniform, high-quality metal layers on a substrate to form sub-micro features. There is also a need to form a metal layer on a substrate having a high aspect ratio micron size that fills the feature without voids in the feature.

SUMMARY OF THE INVENTION The present invention provides an apparatus and method for obtaining a reliable, constant metal electroplating or electrochemical deposition on a substrate. In particular, the present invention provides deposition of a uniform, void-free metal with a substrate having a submicron shape formed thereon and a metal seed layer formed thereon. The present invention provides an electrochemical deposition shell comprising a substrate holder, a cathode for electrically contacting the substrate plated surface, an electrolyte inlet adapted to receive the substrate, an electrolyte vessel having an electrolyte outlet and a number of cells, and an anode electrically connecting to the electrolyte .

The shape and dimensions of the deposition shell and components are designed to provide a uniform current distribution across the substrate. The shell is provided with a diaphragm unit which provides a combination of a through flow anode and a fairly uniform flow of the particulate free electrolyte so as to maintain its shape. The stirring device may also be mounted to the substrate holder to vibrate the substrate in one or more directions, i. E., X, y and / or z directions. The auxiliary electrode may also be disposed adjacent the electrolyte outlet to provide uniform deposition of the substrate surface and to create an electric field at the edges and contacts of the substrate as needed. In addition, a time-varying current waveform comprising periodic reverse and pulsed currents may be applied during the plating period to provide a voidless metal layer within the sub-micron shape on the substrate.

An apparatus for electrochemically laminating metal on a substrate having a substrate-plate-shaped surface,

A substrate holder applied to support the substrate at a location where the substrate plate-shaped surface is exposed to the electrolyte in the electrolyte container, a cathode in electrical contact with the substrate plate-shaped surface, an opening adapted to receive the substrate plate- An electrolyte outlet including an electrolyte outlet, and an electrolyte inlet, and an anode electrically connected to the electrolyte.

The effect of the present invention is more understandable when referring to the embodiment.

The present invention provides a method of operating a cell for depositing a qualitatively high metal layer on a substrate and multiple embodiments of new electrochemical cells. The present invention also provides a new electrolytic solution beneficial for laminating metals, particularly copper, in a very small form, for example a micron-sized shape. The invention will first be described in relation to the hardware, and the operation of the hardware and the chemical composition of the electrolyte solution are described below.

The electrochemical cell hardware is a schematic cross-sectional view of a cell for electroplating a metal onto a substrate. The electroplating cell has a container body, the container body having an upper portion thereof open to receive and support the substrate holder

There is. The container preferably consists of an annular cell composed of an electrically insulating material such as plastic, plexiglass (acrylic product), Lexan, PVC, CPVC and PVDF. Alternatively, the container body may comprise an insulating layer, such as Teflon, PVDF, plastic or rubber, or a combination of other materials that can be electrically insulated from the electrodes of the cell (e.g., the cathode and anode) Such as nickel, titanium, or stainless steel. The substrate holder is used as an upper cover for the container body and has a substrate support surface stacked on the lower substrate. The container body is formed to a size suitable for the shape of the substrate passing therethrough, and is usually formed to fit the size of the stacked area in the form of a square, a square, or a circle.

An electroforming solution inlet disposed on the lower surface of the container body is disposed. The electroplated mold solution is pumped into the container body by a suitable pump connected to the inlet so that the substrate flows into the interior of the navigation container body and comes into contact with the exposed substrate surface.

The substrate is fixed on the substrate support surface of the substrate holder, and preferably at a constant surface, a plurality of passages are held in vacuum to form a vacuum chuck (not shown). The cathode contact member is arranged on the lower surface of the substrate holder and supports the substrate on the container. The cathode contact member includes at least one contact portion that provides an electrical connection between the power supply and the substrate. The cathode contact member comprises a plurality of inductive contact fingers or wires in electrical contact with the substrate surface or a continuous induction ring.

The coating material prevents plate contact and can predict the conduction characteristics through contact with the surface of the substrate. The contact member is made of a stable metal in the chemical environment of the cell, but is preferably protected by an insulating sheet, a polymer gasket or a coating if it can be coated with copper through a plate process such as platinum, gold and alloys thereof.

The contact is advantageously coated in the contact area with a material that provides low contact resistance to the substrate surface, particularly a material that provides low contact resistance to the substrate. For example, copper or platinum. The negative electrode contact member 52

Plating for the contact area changes the physical and chemical features of the conductor and ultimately weakens the contact performance, leading to plate-like deviations and defects. Therefore, the contact area is formed by a coating or gasket on the contact member outside the contact area physically contacting the substrate, an electrolyte

. Such contact materials include PVDF, PVC, Teflon, rubber or other suitable elastomers. If the contact member is constructed in a plate shape, a positive current is passed through the intermittent contact for a short time for the de-plate shape of the contact member. The negative electrode for this recovery process is a positive electrode (reverse biased) or a negative

May be an auxiliary electrode described in Fig.

Typically, one power supply is connected to all the contact pins of the cathode contact member, resulting in a parallel circuit through the contact pins. When the pin-to-substrate interface resistance is changed between pin positions, more current flows, so that more plate formations occur at the lowest resistance position. However, since the external resistors are successively placed on each contact pin, the amount and value of the current passing through each contact pin is mainly controlled by the external resistor. This is because adding the overall resistance of each contact pin-substrate contact to the control resistor bifurcation of the power supply to the substrate circuit is substantially the same as that of the control resistor. As a result, the deviation of the electrical properties between the contact pins does not affect the current distribution on the substrate, and a uniform current density is required in order to maintain the plate-

Across the plate surface. To provide a uniform current distribution between each contact pin 56 for a radial array shape of the cathode contact member 52 during plate-shaped cycles on a single substrate and between multiple substrates in a plate-like state, (58) is in continuous contact with each contact pin (56).

Preferably, the resistance value of the external resistor (REXT, 58) is greater than the resistance value of the other component of the circuit. As shown in Fig. 4, the electrical contact through each contact pin 56

Is represented by the resistance of each component connected in series with the power supply. RE represents the resistance of the electrolyte, which is typically dependent on the constituents of the electrolyte solution and the distance between the anode and cathode. RA represents the resistance of the electrolyte adjacent to the surface of the substrate plate in the boundary layer and the double layer. RS represents the resistance of the substrate plate shape surface

And RE denotes the resistance of the cathode contact pin 56. [ Preferably, the resistance value of the external resistor REXT is greater than the total of RE, RA, RS and RC, for example REXT > 1 OMEGA, preferably REXT > The external resistor 58 also provides a uniform current distribution between the different substrates in a continuous process.

The substrate is plate-like, and the contact-pin-substrate interface resistance is varied through a number of substrate cycles, ultimately reaching unacceptable values. The electronic sensor / alarm 60 may be connected via an external resistor 58 to adjust the voltage / current through an external resistor to reach this problem. Voltage / current through external resistor 58

When the high pin-to-board resistance indication falls outside the operating area, the sensor / alarm (60) triggers are precisely measured, such as blocking the plate process until the problem is corrected by the operator. Alternatively, each power supply may be connected to each contact pin and controlled and adjusted, respectively, to provide a uniform current distribution across the substrate.

As an alternative to the contact pin arrangement, there is a cathode contact member 52 with a continuous ring in contact with the circumferential edge of the substrate.

In one embodiment, the substrate is fixed in the substrate holder by a vacuum chuck,

The elastomeric (e.g., silicone rubber) ring 62 is loaded against the pole contact member 52 to seal the backside of the substrate 48 from the electroplating solution and to the cathode contact member 52 And is partially disposed within the substrate holder 44 to enhance the load on the substrate. The elastomeric ring 62 shown in Fig.

Although it is used efficiently, it is composed of a wedge shaped ring. The elasticity of the elastomeric ring, when compressed by the substrate, exerts a force on the substrate to provide good electrical contact with the cathode contact member 52 and provides a good seal for the backside of the substrate 48.

The substrate holder 44 is preferably attached to the elastomeric ring 62 for electrical contact between the substrate plate shaped surface 54 and the cathode contact member 52 Includes an adjacent inflated bladder (64). The gas-inflated bladder (64) comprises an elastomeric ring

Is arranged in an annular cavity adjacent to the elastomeric ring 62 and can be expanded by a gas for applying pressure on the elastomeric ring 62. The gas exerts a force on the substrate to pressurize the elastomeric ring 62 and bring the substrate into contact with the contact member. In order to reduce the contact pressure between the elastomeric ring 62 and the backside of the substrate 48 the relief valve draws gas from the gas inflow bladder 64 to move the elastomeric ring 62 into the substrate holder 44 Lt; / RTI >

Because the substrate holder 44 is positioned over the container body, the substrate plate-shaped surface 54 of the substrate is brought into contact with the opening of the container body. The substrate holder 44 is disposed on the outer ring 66 connected to the top of the container. An insulating O-ring 66 is positioned between the substrate holder 44 and the outer ring shoulder 66. Preferably, the substrate holder 44 includes a beveled bottom 70 corresponding to the beveled top edge 72 of the container body. The cone

The upper edge of the inner body forms at least a partial circumferential outlet 74 between 1 mm and 30 mm between the container body and the substrate holder 44 for electrolyte flow. The outlet 74 preferably extends around the container body and the cover,

The width of the exit can be adjusted by raising or lowering the substrate holder relative to the upper surface of the container body,

have. Preferably, the outlet is between 2 mm and 6 mm. The outlet 74 has a narrow and inclined shape to enhance the outer flow of the electrolyte and to minimize the congestion corner where bubbling occurs.

The ring 80 or the sleeve insert 80 disposed at the top of the container body is used to accurately form the plate-like area of the substrate. The insert 80 may be modularly adapted to apply electroforming cells of various sizes including 200 mm and 300 mm and having a shape including a circle, a square, a square, and the like. The size and shape of the container body may be varied correspondingly for the size and shape of the substrate to optimize the size and shape of the substrate

All. The insulator 80 insulates the edge of the substrate 48 and restricts current flow to the circumference of the plate surface to prevent the edge from becoming a non-uniform plate. Thus reducing the fringing effect encountered when the cell size is greater than the plate-shaped surface.

When a plate-like image is formed on the substrate, ions are deposited on the substrate from the solution. Providing additional plate material

For this reason, the ions are diffused through the diffusion boundary layer adjacent to the plate-shaped surface. Typically, in the prior art, deficiencies are supplied via hydraulic dynamical means by solution flow to the substrate and rotation of the substrate. However, the hydraulic dynamical replenishment method was an insufficient supplement because it was a no slip condition in the boundary layer. On the other hand,

The electrolyte adjacent to the plate-shaped surface is brought into the zero velocity and the stationary state. Explain these limitations and increase the supplement

A vibrating member 82 is provided on the surface of the substrate to control a large amount of transporting ratio (boundary layer thickness). The oscillating member 82 is preferably mounted to the substrate holder 44 to oscillate the substrate 48. The oscillating member 82 typically includes a motor or a vibration transducer that moves the substrate holder 44 back and forth along one or more axes at a frequency of about 100 Hz to 20,000 Hz. The amplitude of the vibration is formed between about 0.5 microns and 100,000 microns. The vibrating member 82 provides additional vibration in the second direction and the second direction is parallel to the substrate plate shaped surface such as to vibrate the substrate in the x and y directions. Additional vibrations may be provided diagonally across the feature surface. Alternatively, the oscillating member 82 may be configured to move in the xy-

the substrate may be vibrated in various directions, such as in the z direction.

The frequency of the oscillation can be synchronized to the plate shape cycle (described in detail below) to suitably accommodate the large amount of feed ratios required for the laminating process. Conventional electroplating systems are concerned with this feature because there is no high frequency disturbance or reversal in the reduced electrolyte flow due to fluid inertia in conventional electroplating systems. Vibration is achieved by removing the rinse solution and residual plate form from the substrate surface after completing the plate-

.

The substrate holder 44 is partially or wholly rotated in addition to oscillating rotation to further improve uniform plate thickness. A rotary actuator (not shown) may be attached to the substrate holder 44 and the pins and partially rotates the substrate holder relative to the central axis through the center of the substrate holder in an oscillatory manner.

The rotational movement of the plate-shaped surface relative to the electrolyte improves the exposure of the fresh electrolyte across the plate-shaped surface to improve the uniformity of the deposition.

Another advantage of vibrating the substrate 48 is that the vibrations are exposed to deflection and bring the new electroplating solution closer. When the solution adjacent to the substrate depletes the layered metal, the reciprocating movement of the substrate is provided in the region adjacent to the vias, providing a fresh electroplating solution with a high concentration of copper or other metal. This is accomplished by translating the mouth of the trench or vial on the substrate plate-shaped surface into the area of the solution. The solution does not encounter trenches or vias, and therefore the bottom of the reactant leads to depletion. An alternative to vibration of the substrate 48 and the substrate holder is the vibration of the electrolyte. A vibration transducer (not shown) is positioned within the container body to directly vibrate the electrolyte. Further, the vibration transducer is placed on the outer surface of the container body,

To vibrate the electrolyte indirectly. The vibrating member 82 moves from the plate-like member 54 and increases the formation of the bubble to be removed from the cell, thereby eliminating the bubble-related defects.

Gas bubbles may be transported to the electrolyte flow through the system or trapped in a substrate fixture in a cell that is biased by an electrochemical reaction at the cathode or anode. The gas bubbles are preferably discharged from the cell to prevent defects in the plate-like process. A plurality of gas conversion vanes may be disposed over the anode to change the gases entrained in the sidewalls of the electrolyte container. In general, gas bubbles move to higher heights due to their lower specific gravity and flow with the electrolyte. The electrolyte flows upwardly outward relative to the substrate. Vibration is applied to the electrolyte, or the substrate support member removes the bubble from the substrate surface and improves the movement of the gas bubble from the cell. Preferably, a plurality of degassing ports are disposed adjacent the periphery of the substrate support surface through the substrate holder 44 to remove gas bubbles from the cell. The gas removal ports 81 prevent leakage of electrolyte through the gas release slots,

And is positioned at an upward angle to remove the gas bubbles. A number of suitable measurements may be used to prevent electrolyte spillage from the degassing port 81. First, the gas removal ports 81 are positioned higher than the upper portion in the static state of the electrolyte. Second, the degassing ports can be treated hydrophobic by removing the Teflon tube. Third, the calculator gas pressure sufficient to prevent the outflow of solution can be applied externally through the outflow of the degassing port. Finally, the gas removal ports are covered with a small volume of container sufficient to hold the gas bubbles.

Further, in the cathode electrode and the anode electrode, the auxiliary electrode is disposed in contact with the electrolyte to change the shape of the electric field on the substrate plate surface. The auxiliary electrode 84 is preferably positioned outside the container body to control the stack thickness, current density, and potential distribution in the electroformed cell to obtain the desired electroplating on the substrate.

The auxiliary electrode 84 should preferably be mounted on the container body since the copper layer is formed on the auxiliary electrode 84 when the auxiliary electrode 84 is made to be a cathode and the deposited copper is released or decomposed when the auxiliary electrode 840 is polarized With the auxiliary electrode 84 positioned within the container body, the non-adherent laminate is crumpled or the degradable particulate material is in solution and contacts the substrate plate shaped surface 54 to cause defects or damage on the substrate.

In addition, since the electrolyte flow rate is relatively high outside the container body, the non-adherent laminate material flows through the non-adherent laminate material, The positive electrode layer 84 is formed on the auxiliary electrode 84,

Less. The advantage of positioning the auxiliary electrode outside the container body is that the periodic maintenance is facilitated by placing the other modular auxiliary electrode unit in the electroforming cell. However, when the auxiliary electrodes are located inside the container body, they cause high uniformity of the lamination and a high degree of control.

The auxiliary electrode 84 may be comprised of an array of spaced apart electrodes, a ring, a series of center rings, or a series of segmented rings to match the corresponding array of cathode contact pins 56. The auxiliary electrode 84 is positioned on the changeable plane or on a plane such as the substrate plate shaped surface 54 for better current and potential distribution on the substrate 48.

Optionally, the plurality of center ring auxiliary electrodes are configured in a manner to continuously activate the potentials or activate the different potentials according to a desired process. Figure 3 shows the shape of an auxiliary electrode 84 with an array of segmented electrodes matched with an array of cathode contact pins to overcome the effect of isolated contact, Localize. The auxiliary electrode 84 forms an electric field by homogenizing the local effect of the isolated contact. The auxiliary electrode 84 can be used to eliminate the hostile effect of the resistive substrate on the stack thickness distribution by changing the current / potential according to the deposition time and thickness. The current / potential auxiliary electrode 84 can be dynamically adjusted from a high current level during the initial stage of electroplating to gradually decrease the current / potential when the electroplating process is continuous. The auxiliary electrode is cut off before the final step of the electroplating process and can be programmed to suit various processes. The use of auxiliary electrodes can eliminate the need for physical, non-adjustable cell hardware to reduce the initial resistive substrate effect. In addition, the auxiliary electrode can coincide with the reverse plate-shaped cycle, thereby providing further favorable matching properties.

Optionally, the auxiliary electrode comprises a segmented inversion material having a plurality of contact points such that the potential of the auxiliary electrode is displaced to a different distance from the point of contact. This shape provides a corresponding different potential for the shape of the separated cathode contact member. The difference in the auxiliary electrode is such that an efficient high potential (and current) is provided at the substrate contact point of the cathode contact member, and an efficient low voltage (and current) is provided in the region between the substrate / Thereby providing a variable width electrode corresponding to the shape of the fin. Since the effective voltage provided by the auxiliary electrode with a variable width is reduced when the distance is increased between the edge of the substrate and the auxiliary electrode, the auxiliary electrode of variable width is positioned between the edge of the substrate on which the anode contact member is located and the auxiliary electrode

Confidentiality of the distance.

Preferably, the consumable anode 90 is disposed in the container body to provide a metal source in the electrolyte.

The fully self-enveloping module, the soluble copper anode 90,

. The module anode is comprised of a metallic part 92, such as high pure copper, surrounded by a porous cover 94, a metal wire, or a perforated or solid metal sheet. In one embodiment, the lid 94 is comprised of a porous material, such as a polymeric membrane or ceramic, over which the metal part 92 is enveloped. The positive electrode contact 96 is inserted into the lid 94 in electrical contact with the metal part 92. A positive electrical contact 96 is connected to the power supply 49 for providing power to the anode and is made of an insoluble material such as titanium, platinum, or platinum-coated stainless steel. The porous sheet of lid 94 serves as a filter to provide an electrolyte-free component to the substrate plate-shaped surface 54 because it retains the particulate matter generated by the decomposition metal within the anode surrounded by the filter. Solubility

The copper anode 90 provides an electrolyte-free gas into the solution, unlike processes using an insoluble anode that emits a gas, and minimizes the need to uniformly supplement the copper electrolyte. The metal part 92 is formed in the electrode or in the form of an envelope, wire, or pellet surrounded by the electrode. This shape provides a passage and a high surface area for electrolyte flow. The high surface area of the metal parts is oxidized

The reaction and polarization are minimized and cause a moderate current density for the copper plate shape during the substrate anodisation step of the periodic reverse plate shape cycle (described in detail below). If it is desired to have a small surface area exposed to the electrolyte due to further excessive decomposition on the anode,

It is preferable to contact the downward contact surface (the surface against which the flow flows).

Preferably, the anode 90 is comprised of a modular unit that can be easily replaced to minimize obstruction and facilitate maintenance. Preferably, the anode 90 is bonded to the substrate plate surface (54, 200 mm substrate)

Are located at a large distance, preferably at a distance greater than 4 inches. Hence, different effects of level in the anodic copper generated by assembly error, specific fluidization and anodic degradation can be ignored when the electrolyte flow reaches the substrate surface.

A weir plater similar to the components of the electroplating cell described above. However, the container body includes an upper annular weir 43 having an upper surface having a height approximately equal to the plate-shaped surface. Thus, the plate-like surface is in full contact with the electrolyte even when the electrolyte flows downward from the electrolyte outflow gap 74 to the bottom. Optionally, since the upper surface of the weir is positioned slightly lower than the substrate plate shaped surface, the substrate plate shaped surface is positioned just above the electrolyte as the electrolyte flows over the weir. The electrolyte may have a meniscus property (e.g., capillary

Shape) of the substrate plate surface. In addition, the auxiliary electrode is relocated very close to the electrolyte effluent so that the electrode is in effective contact.

A flow regulator (110) with a cone-shaped profiled porous barrier of varying thickness is disposed in the container body between the anode and the substrate to improve flow uniformly across the substrate plate-shaped surface. Preferably, the flow regulator 110 is used to provide a differentiation of the electrolyte flow at a location that is spaced across the plane of the substrate

A porous material such as a polymer or a ceramic. Figure 5 shows the electrolyte flow between the substrate plated surface and the porous barrier along arrow A. The flow regulator 110 navigates the center of the structure, i.e., the center of the wafer. Thus, since the flow of the electrolyte to the center of the substrate is increased through this region,

Ensure that the electrolyte flow across the surface is uniform. Without the flow regulator, the electrolyte flow increases from the center of gravity to the edge because the electrolyte effluent is made adjacent to the edge. In addition, the cone-shaped flow regulator 110 is inclined from the substrate surface, extending away from the substrate surface at the edge of the substrate

do. Preferably, the increased tapered cone shape and thickness of the flow regulator are optimized according to the size of the substrate plate shaped surface and the desired electrolyte flow, thereby making the electrolyte flow uniform across the substrate plate shaped surface. A similar effect occurs in apertured plates. The size and space for the perforations produce a predetermined flow distribution

.

A broken substrate catcher (not shown) is positioned within the container body to catch the broken substrate portion.

Preferably, the broken substrate catcher comprises a mesh, a porous plate or a membrane. The above-described porous wedge-type or apertured plate is used for this purpose.

Refining electrodes (not shown) are located on the islands (not shown) for pre-electrolysis of the electrolyte, for removal of the metal, and for other chemical depositions on the sump. Tablet type electrodes are operated continuously or periodically according to the needs of the system. When the tabular electrode is made of copper and has bipolarity, the electrode is used to replenish the copper in the bath. These external electrodes can be used to precisely adjust the copper concentration in the bath.

A reference electrode (not shown) is used to accurately determine the polarity of the cathode, anode, and auxiliary electrode.

When the electroplating process is completed, the electrolyte is discharged from the container body to an electrolyte reservoir or a sump, and a gas knife is used to remove the electrolyte film remaining on the substrate plate surface. The gas knife has a gas inlet, such as an elongated air tube or a shrinkable tube, connected to a hollow cathode electrode and provides a gas / fluid dispersion or gas stream that pushes the electrolyte away from the substrate surface. The gas is supplied through the gap between the container body and the substrate holder and flows over the substrate surface.

 Thus, the boundary scattering layer is minimized during deposition. Also, by removing vibration during the disassembly interval, the disassembly process under a large amount of feed is controlled.

In order to improve the adhesion of the metal to the seed layer during the formation of the very short plate shape, a strike of high current density is applied at the beginning of the plate-shaped cycle. To minimize the bubble related defects, the blow is made short and the current density should not exceed the value at which hydrogen is released. This current density, preferably a current density of about 100 mA / cm 2 to 1000 mA / cm 2, corresponds to an overcharge that does not exceed -0.34 V (cathode). Each striking process using a different electrolyte may be required for attachment of the metallic sheet material. Each striking is done in the same cell by guiding and removing the different electrolytes in each cell, or with different electrolytes. The electrolyte used for each striking thinner metal concentration, and may also consist of a cyanide-based formula.

The metal seed layer is sensitive to dissolution in the electrolyte by the exchangeable current density of the electrolyte (approximately 1 mA / cm 2 for copper).

For example, 1500 ANGSTROM of copper is decomposed for about 6 minutes in an electrolyte to which no current is applied. In order to minimize the risk of the seed layer being dissolved in the electrode, the voltage is applied to the feedback before the substrate is guided to the electrolyte. Optionally, the current is applied immediately when the substrate is brought into contact with the electrolyte. When the lamination current is applied to the substrate plate surface, the metal seed layer is protected from decomposition in the electrolyte since the lamination current is dominant over the equilibrium recycling current density of the electrolyte.

The present invention may also be provided for in situ electroplanarization during a periodic reverse plate shaping process. Preferably, at the end of the process, the trenches, via, and other connection features are completely filled and plate-shaped, since the two stacking and disassembling steps are done in a single pulse or a successively fast pulse. The electrochemical plate shaping step comprises applying a high current density during the decomposition. E.g,

A decomposition reversal current density of about 300 mA / cm 2 is applied for about 45 seconds as an electrochemical plate-forming step, which results in a nearly flat surface with residual dimples of about 0.03 μm. Such an electrochemical plate

Shaping reduces the need for chemical mechanical polishing (CMP), and even in some applications removes CMP itself.

Electrolytes having a high chemical copper concentration (e.g., between 0.5M and greater, preferably between 0.8M and 1.2M) are beneficial to overcome the limit of the plate shape of sub-micron features (huge transport limit). In particular, since sub-micron features with a high aspect ratio allow only minimal flow, or allow non-electrolytic flow,

So that the metal of the small feature is laminated. A high copper concentration of about 0.8 M or more in the electrolyte improves the dispersing process and eliminates the large transport limitations because the dispersed flux is proportional to the electrolyte concentration. A preferred metal concentration is about 0.8 to 1.2 M or so. However, in general, the higher the metal concentration, the less the metal salt should approach the appropriate solubility limit.

Conventional copper plate electrolytes contain a high sulfuric acid concentration (about 1 M) to provide high conductivity to the electrolyte.

While the preferred embodiments of the present invention have been described above, it will be appreciated by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

It can be done without leaving. The scope of the invention is determined by the appended claims.

Claims (8)

An apparatus for electrochemically laminating metal on a substrate having a substrate plate-shaped surface, the apparatus comprising: a substrate holder applied to support the substrate at a location where the substrate plate-shaped surface is exposed to an electrolyte in the electrolyte container; An electrolyte container comprising an anode in electrical contact with the electrolyte, an anode in electrical contact with the electrolyte, an opening adapted to receive the substrate plate-shaped surface, an electrolyte outlet, and an electrolyte inlet, and an anode electrically connected to the electrolyte. 2. The apparatus of claim 1, wherein the substrate holder comprises: a vacuum chuck having a substrate support surface;
And an elastomeric ring disposed about the substrate support surface and contacting the circumference of the substrate. 3. The apparatus of claim 2, wherein the support holder further comprises at least one bubble removal port having at least one opening adjacent the edge of the support surface. The apparatus of claim 1, wherein the support holder comprises: a vacuum chuck having a substrate support surface;
And a gas bladder disposed about the substrate support surface and adapted to contact the circumference of the substrate. The fuel cell system according to claim 1, wherein the anode comprises: a flowable porous cap of an electrolyte;
A metal disposed in the lid, and an electrode disposed through the lid and electrically connected to the metal. 6. The apparatus of claim 5, wherein the metal comprises at least one material selected from the group consisting of metal pellets, metal wires, and metal particulates. The device of claim 1, wherein the cathode comprises a cathode contact member disposed in a circumference of a substrate plate-shaped surface, the cathode contact member having a contact surface adapted to be in electrical contact with a substrate surface . 8. The apparatus of claim 7, wherein the cathode contact member comprises an array of radial contact pins.