TWI230413B - Treatment method for protecting metal surface of semiconductor structure - Google Patents

Abstract

This invention provides a treatment method for protecting metal surface of semiconductor structure, which comprises at least providing a semiconductor structure with a metal layer thereon, and forming a passivation layer on the metal layer of the semiconductor structure, in which the passivation layer at least comprises a metal oxide layer. The invented method is particularly applied on the semiconductor structure with electrochemical copper surface component.

Description

1230413_ V. Description of the invention (1) 5-1 Field of invention: The present invention relates to the manufacture of general ultra-large integrated circuits, in particular to a treatment that protects the copper surface of semiconductor structures before and after mechanical grinding. method. 5-2 BACKGROUND OF THE INVENTION When the appearance size of integrated circuits is reduced, the efficiency of internal components tends to be mixed. This is a natural representation of semiconductor physics; that is, the speed and functional capabilities of components will increase simultaneously. In any case, the overall circuit speed depends more on the delay speed of the interconnect lines connecting the internal components. With the advent of extremely large and very large integrated circuits, the characteristics of interconnecting conductors forming elements and metal conductors between circuits in semiconductors with high signal transmission and low resistance are becoming more and more important; steel due to its low resistivity and The low resistance values of electromigration and stress volatility make them popular.

It has been observed that 'lithography and metal are semiconductors, semiconductors, and semiconductors, and are etched to form the interconnected layer required for the formation process of the TH cracking process; furthermore, a sigma wound and both Is it very abandoned? Decay + It is difficult to carve copper. The above obstacle is also the reason why the current large-scale integrated circuit 1 I is too early to connect to different layers. Use aluminum and tungsten blades as the connection and plug I; However, copper j

1230413 V. Description of the invention (2) Properties and low resistance value. Therefore, copper is more suitable for connection and plug than aluminum. In addition, copper has better electrical properties than tungsten, making copper an ideal plug substance. In this way, under the easy etching method such as depositing aluminum or tungsten to form a connection and a plug, etching copper must take more time and cost. Based on the above, chemical machine research has become the best choice for removing unwanted copper. Generally speaking, the copper surface is formed by chemical electrolytic deposition in a solution containing copper sulfate. After the chemical electrolytic deposition method, the wafer is washed with deionized water. However, the copper surface of the wafer is very susceptible to contamination by residues. On the other hand, in the CMP process, the action of picking up the wafer with a robotic arm is likely to accelerate the corrosion of the copper grain-to-grain interface. In addition, during the interval between the chemical mechanical polishing method and the previous step, the copper surface was exposed to the outside and easily oxidized again. According to the above, the high reactivity of the copper surface makes it very important to avoid oxidation and corrosion in the copper process. -3 Purpose and Summary of the Invention: In view of the above background of the invention, the present invention provides a method for protecting the surface of a semiconductor structure metal; the surface of the semiconductor structure metal can be protected from oxidation and from epitaxial corrosion caused by residues. influences

1230413 V. Description of the invention (3) The properties of the product should be reversed, the surface should be copper, the copper should be round, the crystals should be protected, and the corrosion should be protected. For the warp surface raised from above, the copper in the table is revealed in the hair, which is shown in the oxygen, which is a half of the life of this method, and it is shown in the upper layer of the metal body Jin Jindaoyi ’s semi-structured protective structure, structure-protected structure, and structured exposed body are semi-exposed. The half-layered one-piece eye protection for the protection is included in the package, which is less and even more, according to the law. The structure of the square structure is half used by the Ying Weng method. Send the element on the Ming. Layered Surface Oxygen | Copper-Gold One Chemical'-Electricity Includes Packages Up to Structured Junction Guards 5-4 Detailed Description of the Invention: The semiconductor design of the present invention can be widely applied to many semiconductor designs, And it can be made with many different semiconductor materials. When the present invention is described with a preferred embodiment of the present invention, those skilled in the art should recognize that many steps can be changed, and materials and impurities can be replaced. These general substitutions also undoubtedly do not depart from the spirit and scope of the present invention. Secondly, the present invention is described in detail with a schematic diagram as follows. In the detailed description of the embodiments of the present invention, the cross-sectional view showing the semiconductor structure will not be partially enlarged according to the general scale in the semiconductor manufacturing process to facilitate the description, but it should not be limited to

Page 6 1230413 V. Description of the invention (4) It should include the cognition of length, width and depth. In addition, the actual three-dimensional space size is moderate. In this embodiment, exposing a protective wafer metal surface includes at least providing a wafer with a metal layer on the wafer; the first two are treated with an i-containing liquid containing an inhibitor when the first two are present in the wafer. e is $ 2, 2 faces ^, that is, a protective layer is formed by the reaction between the inhibitor and the metal | 22 is 22 to form a consistent dense metal oxide layer to protect the wafer from oxidation and corrosion. The first picture shows the use of chemical mechanical polishing equipment to complete the formation of a protective layer on the copper surface of the wafer. A schematic. First of all, the electronic signal response 11 of the mechanical arm 丨 2 used to hold the wafer in the chemical mechanical polishing method equipment is used to control a motor 13. The motor 13 is used to control the solution inlet from a storage tank 14 to an end 15. When the electronic signal response is detected, it is sensed that the circle 16 is held by the robot arm 12 and the electronic signal response 11 is sent to the motor 13 'The motor 1 3 starts to run to deliver a BTA (Benzotriazole) containing Solution. The BTA-containing solution in the storage tank 14 is suitable for forming a protective layer on the copper surface of the wafer 16 formed by the electrolytic chemical deposition method. Through the pipeline 17 and the motor 13, the BTA-containing liquid flows from the storage tank 14 to the end 15 such as a nozzle; then the BTA-containing solution is sprayed on the copper surface of the wafer 16 and wetted to make a layer such as oxidation A protective layer is formed. In this embodiment, considering the compatibility of BTA in the BTA-containing solution, the concentration of BTA is between about 0.1 g / L and 1.0 g / L, and the BTA-containing solution

Page 7 1230413 V. Description of the invention (5) The solvent is water. The oxide layer formed by the reaction between BTA and the copper surface has a dense structure that can prevent further oxidation and erosion of the copper surface. On the other hand, a protective layer on the copper surface of the wafer protects it from chemical attack. In addition, the BTA-containing solution sprayed on the copper surface can be adjusted as long as it can wet the entire surface of the wafer. The second picture shows the operation of the end 15 and the other arm 12 according to the example. What is included in the embodiment is that any mechanical grinding method that can be used for the grinding process can be performed by adjusting the protective layer. Article method. The manipulator used in this study to understand the invention of mechanical research on chemical cleaning. The BTA solution was used to wet the copper surface. Another storage tank containing the BTA solution was used to immerse the entire wafer 16 among them. In any case, when the BTA solution is used to form a protective layer on the copper surface, copper corrosion inhibitors such as BTA can be used in the aqueous solution of the present invention. On the other hand, the present invention is applied to many steps in the copper process, such as pre- and post-chemical steps. It is particularly mentioned that the protective layer can be easily removed during cleaning, without causing the above to describe the preferred embodiments of the present invention, and is not intended to limit the scope of patent application for the present invention; any other Equivalent changes or modifications made without departing from the spirit disclosed by the present invention shall all be included in the scope of patent application described below.

Page 1230413 Brief description of the drawing The invention can be understood more deeply with the following drawings: The first drawing is a schematic diagram of the chemical mechanical polishing method of the present invention; and the second drawing is the chemical mechanical polishing method of the present invention. Another schematic diagram of the main part of the symbol: π electronic signal response 1 2 robot arm 13 motor 14 storage tank 15 end 16 wafer 17 pipeline

Claims (1)

1230413 VI. Scope of patent application 1. A method for protecting a semiconductor metal surface, the method at least comprises: providing a semiconductor structure having a metal layer on the semiconductor structure; and forming a protective layer on the metal layer of the semiconductor structure The protective layer includes at least a metal oxide layer. 2. The method according to item 1 of the patent application range, wherein the above-mentioned metal layer includes at least a copper layer. 3. The method according to item 2 of the scope of patent application, wherein the above-mentioned copper layer is formed by an electrolytic chemical deposition method. 4. The method of claim 1, wherein the forming step includes at least: sensing the presence of a wafer containing the semiconductor structure; treating a surface of the wafer with a solution containing an inhibitor; And forming a protective layer by reacting the inhibitor with the metal layer. 5. The method according to item 4 of the scope of patent application, wherein the solution containing the inhibitor described above comprises at least a solution containing BTA (benzotriazole). 6. The method according to item 5 of the patent application, wherein the concentration of one of the above BTA (benzot r azo 1 e) solutions is about 0.1 g / L to 10 · 0 g / L. Page 10 1230413 VI. Scope of Patent Application 7 • The method of the fourth scope of patent application, wherein the above-mentioned sensing step is to respond by reading an electronic signal holding a wafer. 8. The method according to item 4 of the patent application, wherein the above-mentioned processing step is completed by spraying the inhibitor-containing solution from a nozzle. 9 · The method according to item 4 of the scope of patent application, wherein the above-mentioned processing steps are performed by immersing the wafer in a storage tank containing the inhibitor-containing mash. A method comprising at least: providing a wafer with a metal layer on the wafer; sensing the presence of the wafer, treating a surface of the wafer with a solution containing an inhibitor; and suppressing The agent reacts with the metal layer to form a protective layer. 1 1. The method according to item 10 of the scope of patent application, wherein the above-mentioned copper layer is formed by an electrolytic chemical deposition method. 12. The method according to item 10 of the scope of patent application, wherein the solution containing the inhibitor described above comprises at least a solution containing B T A (b e η ζ τ r i a ζ ο 1 e). 1 3 · The method according to item 12 of the scope of patent application, wherein the concentration of one of the above BT A (1230413 VI, patent scope of benzot ri azo 1 e) solution is about 0.1 g / l to 10 · 0 g / Liter. 14. The method according to item 10 of the scope of patent application, wherein the above sensing step is responded by reading an electronic signal holding the wafer. 15 · The method according to item 10 of the patent application range, wherein the above-mentioned processing step is completed by spraying the inhibitor-containing solution from a nozzle. 16. The method according to item 10 of the scope of patent application, wherein the above-mentioned processing step is completed by immersing the wafer in a storage tank containing the inhibitor-containing solution. 17. The method according to item 10 of the scope of patent application, wherein the protective layer is used to form a uniform dense metal oxide layer to protect the wafer from oxidation and corrosion. Page 12