TWI260715B - Electroplating apparatus - Google Patents

Abstract

An electroplating apparatus which is suitable for depositing a metal layer of substantially uniform thickness across the center and edge regions of a semiconductor wafer substrate is disclosed. The apparatus includes a reservoir for containing an electrolytic fluid. A cathode, to which is mounted a wafer, and an anode in the electrolytic fluid are connected to an electroplating current source. A shield is provided between the cathode and anode to facilitate a more uniform deposit of the metal onto the wafer across the entire surface, including the center and edge regions, of the wafer.

Description

1260715 IX. Description of the Invention: [Technical Field] The present invention provides an electrochemical plating (ECP) device and process for depositing a metal layer on a substrate of a semiconductor wafer when manufacturing a semiconductor integrated circuit, in particular A plating apparatus includes a shield disposed between the anode and the cathode to reduce the rate of deposition of the electric clock around the area of the substrate and to improve the uniformity of the thickness of the metal layer deposited on the entire surface of the wafer. [Prior Art]

In the fabrication of semiconductor integrated circuits, a conductive metal is used as an electrical connection between a plurality of elements. The step of depositing a conductive metal line pattern on the semiconductor wafer includes depositing a conductive layer on the Shixi substrate, and forming a patterned photoresist of the desired metal wire by a standard yellow light technique. Oxygen cut). Next, the engraving is performed to remove the uncharged layer of the cover = 盍 and leave the desired metal wire pattern. Using a typical reactive electropolymerization = the cover layer is bribed out of the conductive gold lining. Subsequent to the substrate of the wafer = conductive material and insulating material, wherein each conductive layer can be filled with conductive material 』 = other metals (four). - China private pool: Shao, tungsten or any other technology can be used to deposit conductive layer on the wafer substrate pressure chemical vapor deposition (LPCVD), __, low-pressure input Shen Qingqing into the milk phase chemical Μ and other pure chip substrates are “, and are the most commonly used to deposit thin layers on wafer substrates to make integrated circuits. Chemical vapor deposition is shrinking due to shrinking semiconductor devices and integrated circuits. The production of the metal interconnected case requires a more fresh two or two forests (four) plus, defined by the yellow light, the curtain technology, the dry _ production 1 = =1 line complexity. First by deposition or succession = 〇 503-A31317TWF(5.0) 5 1260715 or other metal layers are evenly coated on the upper surface. Therefore, the current design is to form a high-quality metal layer, so that the metal layer can effectively fill the extremely small component structure. It is known that the copper system is special = body = in the production, the wire formed by the copper ore can provide a lot of electric forging. "Inverse, including copper can provide a small resistance for a higher operating frequency. In addition, copper has better resistance to electron relocation, which improves the reliability of the entire semiconductor device.

^ Current density and / wire anti-electron migration material green metal inner wire towel-shaped hole or circuit break, resulting in failure or burnout of the entire device. Figure 1 shows a standard or conventional metal deposition (e.g., depositing copper on a semiconductor wafer clock system 10. The electro-mine system 10 includes a standard key unit with an adjustable power supply 12, which stores the electrolytic type. It is a sulfur-solution 16 and a copper metal anode 18 and a cathode 20' in which the electrolyte is impregnated. The cathode 2 includes a semiconductor wafer 22 with a metal ore. The wafer 22 is fixed by a connecting ring 24. 2 阴极 to the cathode.

The electro-hydraulic method can deposit flat copper. The industry is committed to electroplating hardware and can be uniformly deposited on the wafer, suitable for electroplating metal. The anode 18 and the cathode 2 are connected to the power source u using a suitable metal 'wire 26'. The effluent solution 16 may include additives to aid in metal filling and planarization, and the vessel 14 may be coupled to an additional electrolyte reservoir to add additional electrolytic solution to the vessel 14 as desired. The electric power forging system 10 operates the power supply 12 to supply a voltage between the anode and the cathode at room temperature. This voltage produces a magnetic field at the anode 18 and the cathode and affects the distribution of copper ions in the plating bath. A typical copper power provides 2 volts per second for 2 minutes and a current of about 4.5 amps between the cathode 2, anode =, and wafer 22. Next, copper is oxidized at the anode 18 to form a solution to form electrons to reduce the formation of electroplated copper on the wafer 22 of the interface between the sulfur-solution copper foil 22 and the copper sulfate plating bath. The copper oxidation reaction occurring at the anode is as shown in the following reaction formula:

Cu_—>Cu++ + 2e' The oxidation reaction product of copper ion and the sulfate ion of the New Bath 16 towel form ions in the solution towel. 0503-A31317TWF(5.0) 6 1260715 Copper sulfate:

Cu + SO4 — > Cu++ SO ~~ π The electrons obtained from the anode on the wafer 22 are transmitted through the metal line to the copper sulfate ferroelectric (IV). The copper ions are reduced by the electric ore to be reduced on the wafer 22.

Cu++ + 2e -> Cu is deposited on wafer 22 - all of which is copper) before being electrochemically applied to wafer 22. The manner in which the seed layer is provided on the substrate can include any of various ways, such as physical vapor deposition (PVD) and chemical vapor deposition (cvd). — The day-to-day layer is thinner than the conductive metal layer deposited on the substrate of the semiconductor wafer (thickness is about $ ο.: It is a traditional Japanese electroplating technology _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ liquid. Solvent addition adds Xuan Xuanping _, material Ke Tian ==== (four) towel, lion wheel Xie Xiangtian == The quality of copper, metallization quality, electrical and machine age quality have a great impact. However, a disadvantage of the conventional electric ore system 10 is the current density in the middle region of the rim 22 at the wheel 24 . Therefore, the degree of mesh is used to control the thickness of the metal in the area around the substrate to promote the uniformity of the boundary =: electricity = area and surrounding area. BACKGROUND OF THE INVENTION The object of the present invention is to provide an electric weave for surface plating of metal on a circle. The other is to provide a new electric mining device, the metal thickness of the surrounding area. Electroplating on a daily basis Another object of the present invention is to provide a new electroplating apparatus that utilizes ion concentration to control the quality of the metal plated in the area around the wafer. Mine ~ night 0503-A31317TWF (5.0) 7 1260715 A new type of electric weaving, using the electronic path between the cathode of the anode disk into the wafer on the wafer, another object of the present invention is to provide _ pole / crystal A shield between the circles to change the uniformity of the thickness of the metal between the wafer and the anode. A further object of the present invention is to provide a new type of electrical ore 4 for utilizing a pole/wafer shield and a power source electrically connected to the shield to provide a positive or negative response to the enclosure to adjust The metal porch in the Wei bath then uniformly deposits a metal layer in the crystal. ... Shuming's re--the secret of the purpose - a new method of electro-minening, called the geothermal mine on the wafer. To achieve the above and other objects, the present invention provides a new electrical ore device for depositing a metal layer of a thickness-hooked metal layer in the middle of the entire semiconductor wafer substrate and a contact region. The skirt includes a reservoir of a decomposing liquid, a cathode to fix the crystal and an anode to be connected to a power source of the electric clock, and a vessel disposed at the anode and the cathode to promote a more uniform deposition of metal. On the entire wafer surface, including the center of the wafer and the surrounding area. The shield may be lion structure or plate-like and electrically conductive or non-conductive. The non-conductive shield can be modified between the anode and cathode _ current paths in the solution. Therefore, the metal ion distribution of the solution between the mask and the wafer can be changed to uniformly deposit the metal on the entire surface of the wafer, including the center of the wafer and the surrounding area. A conductive shield can be connected to the shielded power source. The switch can be placed between the shielded power supply and the shield. Utilizing the switching enthalpy can provide a negative charge to the mask to serve as a cathode and reduce the cation content of the electrolyte of the pen region. As a result, the metal deposition rate of the plasma in the wafer-off region is reduced as compared to the intermediate region to offset the lower metal deposition rate in the intermediate region of the wafer, thereby increasing the uniformity of thickness of the entire electroplated metal. This switch provides a positive charge to the wiper shield. Therefore, the metal anode of the electrolyte around the wafer will increase in concentration compared to the intermediate region, in order to increase the deposition rate of metal money in the area around the wafer. By alternately making the anus negative charge, the thickness of the metal plating in the area of the crystal can be accurately controlled to form a thickness from the plated metal layer to the entire wafer 0503-A31317TWF(5.0) 8 1260715 The above-mentioned purpose, characteristics, and advantages and disadvantages are applied in detail, and in accordance with the closed type, the details are as follows: [Embodiment] Metal is suitable for the production of semiconductor integrated circuits, electrochemical copper or Other clock metals are not used. In addition, the invention is also generally applied to the field of electrochemical fabrication. The substrate is copper or may be plated with other metals, and is not limited to semi-conductive.

Thickness: Use -= electric and follow W's uniform & electric metal layer thickness liquid between the coffee and medium_domain. The device includes a cathode and an anode for accommodating the electrolyte and connected to the electroless power source, and a side mask to facilitate more uniform deposition of the metal on the surface of the wafer. Center and surrounding area. Structure or - plate structure and includes both conductive and non-conductive. Second, the anti-mosquito can change the circuit between the anode and the cathode in the electrolyte, thereby changing the distribution of the sol-gels, and depositing the metal on the surface of the entire crystal 0, including the center of the wafer and the contact area. 1U曰曰In another embodiment of the present invention, the conductive shielding can be connected to the shielding power source, and the tube is cut into a cathode to reduce the electrolysis of the adjacent region (4) cation Γ ^ ^ rate to the electric chain metal of the kUSl surface The overall thickness is uniform. Electricity ==: Lift: Positive charge to the shield as an anode. Therefore, the metal epoch of the crystal_electrolyte will increase compared with the intermediate region, so that the deposition rate of the metal 〇503-A31317TWF(5.0) 9 1260715 plating around the wafer is increased as needed. The metal is plated on the surface of the wafer to the thickness of the wafer. The positive and negative charges are alternately used by the switch, which can be precisely controlled to form a uniform thickness of the plated metal layer in the whole phase. The plated device can further include a control device to adjust the mask and the wafer in the electric wafer. The charge cathode/shield to the wafer can relatively reduce the rate at which the metal enters the area around the wafer, and by moving the cathode/shield away from the wafer, it can be relatively increased. Following the lazy (10) precision cans are plated to the center of 曰曰0 and the relative thickness of the surrounding area.

Suitable electrolytes include, but are not limited to, sulfuric acid, acetic acid, _acid, methyllithic acid, B: ί - 曱 曱 ? ? ' 'acid, benzoic acid, p-toluene, acid, hydrochloric acid, hydrazine Acids and their analogues. The acid concentration in the electroplating bath is as fine as per liter of gram, including the cesium ion source (eg chloride ion). Suitable copper ion sources include, but are not limited to, copper sulfate, copper chloride, copper acetate, copper sulfide, 1 fiber copper, methyl copper, and copper benzoate to ride the benzene copper. The concentration of the common copper ion source in the electroplating solution is about 10-300 grams per liter.

Other electrochemical plating conditions include electroplating rate of 0-500 rpm, plating current 〇 2-2 〇 mA / cm ^ 2 , plating voltage of about 2 volts, and plating bath temperature of about 1 〇 -35 C) c. In addition, a leveling agent of from about 5 to about 5,000 moles per liter of the leveling agent can be added to the plating bath solution. Referring to Fig. 2, there is shown a cross-sectional view of a plating apparatus 3 according to an embodiment of the present invention. The apparatus 30 includes a standard plating unit having an adjustable power source 32, an electroplating bath vessel 34 having an internal electroplating bath reservoir 35, a typical copper metal anode 36, and a cathode Deng. The connection ring 4 is disposed against the cathode 38 to fix the semiconductor wafer 42 for metal plating. The anode 36 and the cathode 38 are connected to the power source 32 by a suitable metal wire 33. Wherein the electron microscope bath, 34 contains an electrolyte or plating bath solution 44. Moreover, as is known to those skilled in the art, device 30 can further include a mechanical device (not shown) for rotating wafer 42 in the electrolyte during electroplating, and fixing the shield 46 to a technique well known to those skilled in the art. In the electroplating bath container 34, the flail 503-A31317TWF (5.0) 10 1260715 is connected below the %4 crucible. A purely closed towel, the shield % is placed on the arm (10) and connected to the motor 58 of the adjustment position. The towel position adjustment motor % can position the can shield 46 in the vertical position of the container to adjust the shield 46 and the connecting ring 4''.典型 As shown in Figures 3 and 4, a typical shelter 46 includes an annular body 48 having an intermediate shielding opening 5〇. The shielding body 48 can be a conductive metal or a non-conductive material shaft such as plastic or _. When the non-conductive shielding body 48 is utilized, the surface of the shielding body 48 is covered with a conductive material 51, and preferably the conductive material 51 is copper. ^ ... As shown in Figures 3 and 4, the diameter of the annular shield 46 is generally about a millimeter.

ΐΓ5^ΓΓΓ 66"30'50"" °« Adjustment of wafer size. For example, a suitable metal wire is electrically connected to the shield 46, and by means of a switch, you can selectively provide the positive terminal negative end 56b of the power source 56 and the shadow ==. Therefore, as shown by the dotted line, the connection path between the positive W6a and the shield 46 can be established by the switch to selectively provide a positive charge to the shield 46. Conversely, a negative connection can be made by the switch 54 to selectively provide a negative charge to the shield and the connection path between the concealers 46. Referring to Figures 5-7, the system shows another example according to the present invention. The electric woven raft, the basin includes - the hull 72 with the fine-grained domain 74, such as the 帛6 body 74 can be the conductive metal D 戈 non-guided mine (four) "This. β 丨丁« 政主主主74 (four) Μ _ In the case of the thin non-conductive shielding body 74, it is usually covered with copper as the preferred conductive material 76 on the surface of the shielding main (four). Tf /, -H 2 diagram, in the operation of the crane 3G, adding - electrolysis The liquid 44 is in the electric bath bath ageer 35 and immerses the anode 36 in the electrolyte 44. Further, the crystals (4) and 42 are attached to the cathode 38 in the electrolyte 44 by a typical connecting ring 40. The surface power supply 32 provides _ to the cathode 38 0503-A31317TWF (5.0) 11 1260715 and provides a positive voltage to the anode 36. On the wafer 42, the metal ions (eg, steel ions) of the electrolyte 44 are reduced to the electro-layer 43 Because of the presence of the connecting ring, the flow rate of the electrolyte 44 in the area around the wafer 42 is higher than that in the central area of the wafer 42. The metal deposition rate in the area around the wafer 42 is souther than the intermediate area. To reduce the rate of electric ore in the area around the wafer 42, a switch can be utilized to shield the power supply butterfly 56b. The shaft is closed so that the shield in the electrolyte 44 is The cathode, such that the metal ionization of the adjacent mask% is reduced, and the metal atomic bond is formed on the shield 46. Since the metal ion concentration of the electric ship 44 in the area around the wafer 42 is lowered, the metal trace of the wafer 42 touch area Conversely, the deposition speed is reduced. Conversely, to increase the rate of electric ore in the area around the wafer 42, the switch can be connected to the 56 positive end 56a. The _ Μ 正 gives a positive charge to the concealer 46 so that The shielding is an anode, and the metal ion wave length of the area around the solar circle 42 is increased by the conductive material of the shielding material, and the metal electric ship velocity of the display area of the wafer 42 is also increased. The method of controlling the rate of deposition of metal in the area around the wafer 42 further covers the distance between the shield 46 and the wafer 42. Therefore, the gate is supplied with a negative charge to the cathode/shield, then the wafer Around C Part of the rate of deposition of electric ore can be reduced by shifting the ring 40. Conversely, when the switch is provided to the proximity of eight, the electrode is shielded/shield 46, then the wafer is 42 weeks = the plating deposit can be borrowed 46 to the connection ring 4q and increase the position of the position of 7% and the position of the biliary (four) following the position of the electric resistance ^ ",, the eighth item, the fine side of the fine judgment of the county, the electric hard to set 80, here ^ slightly brother 2 In the electronic contact 52 of the embodiment of Fig. 5, the electroplating apparatus 80 includes the anode 36 and the rake and concealing power source %. The /, (3) is adjusted by the position-decreasing motor 58 and the position adjusting arm 6 0503- A31317TWF(5.0) 12 1260715 The whole is up. In addition, the shield 82 may be a non-conductive material (for example, plastic or ceramic), or may be a guide material (for example, copper), and the shield 82 further includes a non-conductive shielding body covered with a conductive material. As shown in the second and fifth embodiments above. Further, the shield 82 includes an annular plate-like structure. ', ° or use the shield 82 to change the metal ion distribution between the anode % and the wafer 42 in the electrolyte 44 at the operating electric woven 8G to reduce the electrolysis money rate in the area around the wafer 42 The deposition rate with the central region of the crucible is roughly _. Therefore, the thickness of the metal layer deposited on the periphery of the wafer and the intermediate zone is substantially uniform. The electronic deposition rate of the exposed areas of the wafer 42 can be increased as needed by the position adjustment motor 58 moving the shield 82 to approach the wafer 42. While the present invention has been described above by way of a preferred embodiment, it is not intended to limit the invention, and the present invention may be modified and stabilized without departing from the spirit and scope of the invention. The maintenance of the U is regarded as the post-consultation t. [Simple description of the diagram] Figure 1 shows a typical sectional view of a typical electric mine system. Fig. 2 is a cross-sectional view showing an electric ore device according to an embodiment of the present invention. Fig. 3 is a top view showing the electric shield of the second figure. The =4 scale shows a section along line 4-4 of Figure 3. ^ shows a cross-sectional view of an electric ore device according to another embodiment of the present invention. Figure 5 is a top view of the plate-shaped shielding element of the electro-mineral device. #回:,,9 shows a sectional view of the 6th line along line 7-7. In the drawings, there is shown a cross-sectional view of an electric clock device according to still another embodiment of the present invention. [Main 符号 symbol description] 10 ~ plating system; 12 ~ adjustable power supply; 0503-A31317TWF (5.0) 13 1260715

14 ~ electroplating bath container; 18 ~ anode; 22 ~ wafer; 24 ~ connecting ring; 30 ~ plating device; 33 ~ metal wire; 35 ~ electroplating bath reservoir; 38 ~ cathode; 42 ~ wafer, 44 ~ electrolyte 48 ~ shielding body; 51 ~ conductive material, 54 ~ switch; 56a ~ positive end; 58 ~ position adjustment motor; 64 ~ diameter; 66 ~ ring thickness; 72 ~ shield; 7 6 ~ conductive material, 82 ~ shelter . 16~ plating bath solution; 20~ cathode; 23~ metal seed layer; 26~ metal line; 32~ power supply, 34~ electric clock bath container; 36~ anode; 40~ connection ring; 43~ seed layer; Masking; 50~shading opening; 52~electronic contact; 56~shielded power supply; 56b~negative end; 60~position adjustment arm; 65~ring width; 70~ plating device; 74~shielding body; 80~ plating device; 0503-A31317TWF(5.0)

Claims (1)

1260715 X. Patent application scope: L A plating apparatus comprising: a reservoir to accommodate an electrolyte; a pole and a cathode, wherein the cathode is used to support a wafer in the reservoir; a current path is interposed between Between the anode and the cathode; and a shield disposed between the anode and the cathode. 2. The device of claim 1, wherein the covering comprises a body of an annular covering. 3. The electroplating apparatus of claim 2, further comprising: a conductive material disposed on the body of the shield. 4. The electroplating apparatus of claim 3, wherein the electrically conductive material comprises copper. </ RTI> </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; 6. If the declaration is specifically for her Wei device as described in item 2, the obscuring material is inclined. a spear 7-electroplating apparatus comprising: a reservoir to contain an electrolyte; an anode and a cathode, wherein the cathode is used to support a wafer in the reservoir; a current path is provided to the anode to the cathode And a mask, including a shield body that is generally plate-shaped, is disposed between the anode and the cathode. 8. The electroplating apparatus according to claim 7, wherein the electroconductive material is provided in the electro-optical device according to the eighth aspect of the invention, wherein the electrically conductive material comprises steel. For example, the electric lining described in item 8 of the profit range includes, for example, shielding the electrical connection surface of the power source to selectively provide a negative charge shield. 11. The electroplating apparatus of claim 7, wherein the shielding body comprises a non- 05O3-A31317TWF (5.O) 15 1260715 - electrically conductive material. 12. A method of electroplating a metal onto a wafer, comprising: k for a reservoir containing an electrolyte; an anode for a cathode and a cathode for the reservoir; &amp; a circuit between the anode and the cathode θ provides a mask in the electrolyte between the anode and the cathode; and provides a current to the 1% pole and the cathode. A method of electroplating-metal on a wafer as claimed in claim 12, wherein the φ shield comprises an annular shield body. The method of applying the electromine-metal to the wafer according to claim 13 further includes a conductive material disposed on the shielding body. The method of electroplating_metal on a wafer according to claim 14, wherein the electrically conductive material comprises copper. _ I6· The method of applying the electromine-metal to the wafer according to claim 14 of the patent scope, further comprising a shielding power supply to provide a sputum charge to the immersion. 17. The method of claiming a battery-metal on a wafer as recited in claim 16 further includes appealing a negative charge to the shield to the iron metal to the shield, and providing positive electricity. The shield is used to release metal ions from the shield into the electrolyte. 18. The method of electroplating a metal onto a wafer according to claim 13 wherein the shield body comprises a non-conductive material. #19. The method of claim 1 , wherein the concealer comprises a shield body that is substantially plate-shaped. The method of applying the electric clock to the metal on the wafer according to claim 19, further comprising a conductive material disposed on the shielding body. 21. The method of claim 1, wherein the electrically conductive material comprises copper. 0503-A31317TWF(5.0) 16 1260715 _, 12 · The method of recording a metal on a wafer as described in claim 20, further comprising electrically connecting the shield to selectively provide 贞Charge to the shield. 3. The method of claim 4, wherein the concealing body comprises a non-conductive material. Optionally, providing a method for recording a metal on a wafer according to the domain item, further comprising charging a charge to the shield to the money metal to the shield, and providing a positive electric current The metal ions are released from the mask to the electrolyte. 0503-A31317TWF(5.0) 17