TW575921B - A method for cleaning particles on the wafer surface - Google Patents

Abstract

A method for cleaning particles on the wafer surface is provided. The method at least comprises a high-speed plug water jet step and an in-situ gas plasma treatment. The high-speed plug water jet is used to remove the particles on the wafer surface and the in-situ gas plasma treatment is used to neutralize the negative charge, which is cause by the high-speed plug water jet, on the core portion of the wafer.

Description

575921 V. Description of the invention (1) Technical jaw field to which the invention belongs The present invention relates to a method for removing fine particles from a manufacturing process, and more particularly to a method for removing fine particles from a wafer surface due to a manufacturing process. Prior art

In the ultra-large integrated circuit (ULSI) process, the wafer cleaning technology and cleanliness affect the quality (Qua 1 ty) and reliability of the wafer fab process Yield components ( Reliability), one of the most important factors, 'especially when the process technician's advanced to the sub-micron area below 0.1 8 / zm, the density of components (devices) reached tens of millions to one billion, the manufacturing process exceeded Hundred steps. To make such a sophisticated product requires a very clean wafer surface to make it. Therefore, how to clean the wafer to achieve the requirement of ultra-cleanness is one of the most important and rigorous steps in the current ULSI semiconductor factory process. The purpose of cleaning is mainly to remove the dirt on the wafer surface, such as particles (Part i cl e), organic (Organic) and inorganic metal ions (Metal

Ions) and other impurities (lmpUrity). In the ULSI process, the gate oxide layer (Gate

The thickness of the oxide is less than 100 angstroms. After cleaning, the micro-roughness of the wafer surface and the native oxide (Native Oxide) are removed to achieve the semiconductor device. Electrical parameters and characteristics of Ultra-Thin Gate Oxide

Page 6 575921 V. Description of the invention (2) Quality and reliability of all parts. In addition to the initial cleaning, the generation of particles during the thin film process is still unavoidable. Some processes are very sensitive to the particles. In order to improve the yield of the process, the particles attached to the surface of the thin film must be removed after the process is completed. In the process of wafer particle removal, in principle, physical cleaning is mainly used. Physical cleaning is based on physical principles and physical actions to clean the wafer without using any chemicals to process the cleaning. The clean technology is mainly to remove the contamination of particles. The most commonly used cleaning method is Jet Spray to remove the particles attached to the wafer surface to reduce the defects caused by particle contamination, which affects the yield. And component quality and reliability. High-pressure spray cleaning generally uses High-speed Plug Water Jet to scrub the surface of the wafer. After wafer cleaning using high-pressure spray cleaning technology, particulate contamination induced by processes such as etching, ion implantation, chemical vapor deposition (CVD), or physical vapor deposition (PVD) is attached to The removal of particles on the wafer surface is very effective. The removal of particles on the wafer surface should improve the yield of the process, but in actual operation, it is found that the yield of the wafer located at the center of the wafer does not increase but decreases. For example, when filling a trench at 0 · 18 microns In the process or (K 1 3 micron copper bimetal inlaid process, the process system of High Density Plasma Fluoro Silicon Glass (HDP-FSG) and Plasma Reinforced Fluorosilicate Glass (PEFSG) results in The main process of component defects is partly due to particle contamination. Particles can be removed after high-speed water jet spraying. Please refer to Figures 1A and 1B. Figures 1A and 1B are the wafers being brushed. Scanning electron microscope images before and after the process. But

575921 V. Description of the invention (3) '" ~ " The yield in the center area of the wafer has dropped significantly by about 20%. This solves the important issue of process formation due to high-speed water jet spray scrubbing. Liang Wu Bu Jiang has become an invention. Therefore, the object of the present invention is to provide a method for removing fine particles in a process, which can effectively remove the fine particles, and can improve the yield of the process. Another object of the present invention is to provide a method for removing process particles, which can avoid the accumulation of charges on the wafer. Yet another object of the present invention is to provide a method for removing fine particles in a process, which can prevent positively charged metal particles from being adsorbed on the surface of a wafer, thereby reducing the yield. According to the above purpose of the present invention, a method for removing process particles is provided. The method disclosed in the present invention includes at least a high-speed water jet spray scrubbing step and an in-situ gas plasma treatment step. The spray-brushing step is to remove particles generated by the process on the wafer. In the same-position gas plasma processing step, when the wafer is sprayed and brushed at a high-speed water column, negative charges will accumulate in the middle of the wafer and cause the middle of the wafer. The part has a high negative potential. If this high negative potential is not eliminated, it will attract the metal material located below and cause the metal material to protrude. Therefore, after the wafers are sprayed by high-speed water jets, the system is neutralized by Insun Water. Charge accumulated on the wafer surface by column jet scrubbing λ

Page 8 575921 V. Description of the invention It is convenient to avoid damage to the wafer by using the same plasma system and plasma system. It can also be changed. The implementation method is now fluorine and oxygen. Fluorine and oxygen are formed. After the wafers are turned into wafers at face-to-face water: the comparison of data. In Figure 2B of the wafer table, the position of the surface potential surface (4) ----- is processed by the bulk and slurry processing steps. A large number of positively charged plasmas used in this step are used to neutralize the wafer. The negative charge, the power plasma 'is the material layer facing the Bombardment effect. In addition to using the same gas plasma, the purpose is to neutralize the negative charge in the shortest time. The day and time are prolonged to increase the negative charge. Of course, the wafer reacts to another plasma. The chamber performs a charge neutralization step. The process of the Shixi glass layer is taken as an example to describe the present invention in detail. The glass deposition process is very prone to particles, so column spray brushing is required to remove the particles. Generally, the yield of the middle part of the fluoroxene glass should be 70% and the area around the wafer should be 54% to be acceptable. However, the middle and surrounding parts of the sheet washed by high-speed water jet spraying are good. The rates are only 59% and 55%. The reason for the sharp decline in yield in the middle part needs to be clarified. Among the various tests and analysis numbers of wafers before and after spraying and brushing, 'a data with a huge difference caused a high level of potential measurement data on the surface of heavy wafers, and the surface potential distributions before and after brushing were greatly different. Please refer to Figures 2A, 2A, and 2B for three-dimensional perspectives of wafer distribution before and after brushing, respectively. The X-axis and γ-axis represent the wafer table (Position) and the potential ( voltage). Please 575921 5. Description of the invention (5) Referring to FIG. 2A, after the fluorosilicate glass layer is formed, the wafer surface shows a positive potential, and the average potential value is about 0.49 volts. The surface potential distribution of the wafer after brushing after the formation of the fluorosilicon slope glass layer is shown in Figure 23, at this time, the surface potential distribution of the wafer has a very large change, not only the electrical changes, the average potential value Lower to -30. 5 volts. In addition, for observation through a scanning electron microscope, please refer to FIG. 3, which is a scanning electron microscope image of a wafer after being brushed by high-speed water jet spraying. The metal material below is attracted by the negative potential. Protruding from the surface of the fluorosilicone glass layer to form metal protrusions 300, more than 700 from the metal dogs with a size of more than 2 microns in the middle part of the wafer, these metal protrusions 300 may cause the underlying metal wires Broken circuit. In addition, in the absence of the fluorosilicone glass layer, of course, in the subsequent process, it is easy to cause metal protrusions and short circuits between the upper metal wires, which will cause the failure of the components. Therefore, high speed The main cause of the decrease in the yield is the negative charge of 1 = knife and volume in the wafer spraying and scrubbing step in the wafer. ; Decision = Circle: A large amount of gas plasma in the middle part is used for processing in the ancient, ^ mouth and disaster wafers, and the crystal plasma is completed after the rapid water jet spray brushing step is completed. Isotopic gas electrode :::; Plasma can be-isopositional gas containing gas, for example, nitrogen; 1 = gas with nitrogen element as the reaction gas any combination. Human plasma I2O, ammonia, or these gases can be used to neutralize the surface of the wafers (Nitrogen cation), which can be brushed and the same gas can be used to feed virtual charges. Please refer to Fig. 4 '. Fig. 4 is a perspective view, and the physical meaning of the three-dimensional representation of the surface potential distribution of the wafer after each coordinate is the same as that of Figs. 2A and 2B. By 4

Page 10 575921 V. Description of the invention (6) It can be seen that the potential on the wafer surface after the plasma gas treatment is changed from -30 · 5 volts in Fig. 2B to 0.24 volts. The previous potentials are equivalent. After scanning electron microscope observation, it was found that as shown in Figure 3, the metal protrusions of more than 2 microns in size did not exceed 100, and the yield in the middle and surrounding parts of the wafer was uniform. Close to about 80% and 60%. Due to the negative charge and continuous accumulation on the wafer surface during the high-speed water jet spray scrubbing process, after the high-speed water jet spray scrubbing step is completed, a large amount of negative charge has accumulated on the wafer surface and the metal located under the fluorosilicate glass layer The layer starts to work. In order to reduce the time of negative potential action, the gaseous plasma is used to neutralize the charge. Of course, if the wafer can be moved quickly, it is also feasible to move the wafer to another reaction chamber for plasma processing. In order to reduce the bombardment effect of the plasma on the fluorosilicate glass layer and the influence on the formed metal layer, the present invention uses a low temperature and low power plasma for processing. The power of the plasma used in the present invention is about 0.1 watts to 600 watts and the temperature is about 25 degrees Celsius to 600 degrees Celsius. The preferred power is about 15 The preferred temperature range is from 0 watts to 400 watts and is between 200 degrees Celsius and 500 degrees Celsius. After the same-position gas plasma treatment step provided by the present invention is used to neutralize the negative charge accumulated on the surface of the fluorosilicate glass layer on the wafer surface due to the high-speed water column jet brushing, not only can the yield of the process be improved, but not only Affects the characteristics of the fluorosilicate glass material, and can also increase the adhesion of the fluorosilicate glass layer. For plasma-reinforced fluorosilicone glass, its adhesion is about 40 kg without any treatment. After being brushed by high-speed water jet, its adhesion is

575921 V. Description of the invention (7) It is slightly reduced to less than 40 kg, but after being treated with high-speed water jet spraying gas and plasma, its adhesive force can reach 45 kg. In addition, the plasma fluorosilicate glass, whether or not after high-speed water jet spray is treated with the same nitrogen, ammonia or ammonia / nitrogen plasma treatment, the dielectric coefficient of | are between 3. 71 3 to 3. 721 的In the meantime, it hasn't changed too much. The water jet spray brushing disclosed in the present invention destroys 32 wafers treated with fluoride with a thickness of 600 angstroms by high-speed water jet spraying, and the 32 wafer-treated wafers are not damaged during high-speed water jet spraying. Although the present invention It has been specified that 'any familiarity here' can be used for various applications attached to the application. The wafers in the silica glass layer that are used to remove the particles in the material layer are removed from the wafer. The wafers with the holes completely brushed pass through the high-speed water jet. The holes are also sprayed and brushed. The surface of the wafer on which the wafer itself is located is exposed in detail. The artist's incessant changes and retouching, the methods defined by the scope can also be used to change the damage caused. The wafer is the object and has not failed at all, but the same, there are 3 wafers. Brushed and pared as before. Therefore, the resulting charge should be caused by the accumulated charge, but it is not intended to limit the spirit of the present invention, so the warranty of the present invention shall prevail. Washing and Paraffin Washing of high-density jets or oxy-silica glass. Large changes in the south speed to deposit without any sample. 32 pieces were broken by 7 holes with ammonia / nitrogen holes. High-speed water column. Defining the hair and scope

575921 Brief description of the drawings In order to make the above and other objects, features, and advantages of the present invention more comprehensible, a preferred embodiment is described below in detail with the accompanying drawings, as follows: Figure 1 A Figure 1 and Figure 1B are scanning electron microscope images of the wafer before and after the brushing process; Figures 2A and 2B are three-dimensional perspective views of the wafer surface potential distribution before and after brushing; Figure 3 It is a scanning electron microscope image of a wafer after being brushed by high-speed water jet spraying, and FIG. 4 is a three-dimensional perspective view of the surface potential distribution of the wafer after being brushed and plasma gas plasma treated. Drawing number comparison description 3 0 0: metal protruding

Page 13 575921 Case No. 91134899_Year Month Day Amendment

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Claims (1)

575921 Case No. 91134899 Amendment VI. Patent Application Scope 1. A method for removing fine particles in a process, the method includes at least: a high-speed water jet spray scrubbing step to scrub at least one wafer; and a plasma processing step to neutralize Charge accumulated on the wafer surface. 2. The method for removing fine particles in a process as described in item 1 of the scope of patent application, wherein the plasma treatment step can use a co-gas plasma. 3. The method for removing fine particles of a process as described in item 2 of the scope of the patent application, wherein the gas system used for the electrosynthesis of the isogas is selected from the group consisting of nitrogen, nitrous oxide, ammonia, and any group and group thereof . 54. The method for removing fine particles in a process as described in item 2 of the scope of the patent application, wherein the gas system used for the isobaric plasma is a nitrogen-containing gas. 5. The method for removing fine particles in a process as described in item 1 of the scope of patent application, wherein the power of the plasma is between about 0.1 watts and 600 watts. 6. The method for removing fine particles in a process as described in item 1 of the scope of patent application, wherein the temperature of the electropolymerization is between about 25 ° C and 600 ° C. 7 · A method for removing particles in a β process, the method at least comprises: a high-speed water jet spray scrubbing step; and a co-gas plasma treatment step; Page 15 575921 VI Case No. 91134899 Scope of Patent Application Correction The high-speed water jet spray scrubbing step is to remove particles on the wafer, and the co-gas plasma treatment step is to neutralize the charges accumulated on the wafer surface due to the high-speed water jet spray scrubbing. 8 The method for removing fine particles of a process as described in item 7 of the scope of the patent application, wherein the gas system used for the isobaric plasma is selected from the group consisting of nitrogen, nitrous oxide, gas, and any group thereof. 9 The method for removing fine particles in a process as described in item 7 of the scope of the patent application, wherein the gas system used for the isogas generator is a nitrogen-containing gas. 1 0. The method for removing fine particles of a process as described in item 7 of the scope of the patent application, wherein the power of the isobaric plasma is between 150 Watts and 400 Watts. 11. The method for removing fine particles in a process as described in item 7 of the scope of the patent application, wherein the temperature of the plasma treatment step is between about 200 ° C and 500 ° C. 1 2 · A method for removing fine particles in a process, the method at least comprises: a high-speed water column spray scrubbing step to remove particles on the wafer; and a nitrogen-containing gas plasma treatment step to provide nitrogen cations to neutralize the high-speed water column spray scrubbing The negative charges accumulated on the wafer surface. Page 16 575921 —-—- 1 ^ _9Π34899 _——------ 6. Application for Patent Scope 1 3 · As described in Item 12 of the Patent Application Scope, the method for removing fine particles in the process' wherein the isotopic nitrogen The gas system used for gas power is selected from the group consisting of gas, nitrous oxide, ammonia, and any group thereof. 1 4. The method for removing fine particles of a process as described in item 2 of the scope of the patent application, wherein the gas system used for the isotope nitrogen-containing gas is a nitrogen-containing gas. 15 · The method for removing fine particles of a process as described in item 12 of the scope of the patent application, wherein the power of the co-gas plasma is about 150 Watts to 400 Watts. 1 6. The method for removing fine particles in a process as described in item 12 of the scope of the patent application, wherein the temperature of the plasma treatment step is between about 200 ° C and 500 ° C.