TWI220170B - Process of probing a wafer - Google Patents

Abstract

A process of probing a wafer includes the following steps. First, the wafer is provided with a passivation layer and at least one contact pad, both of which are on an active surface of the wafer. The passivation layer has an opening exposing the contact pad. Micro-contamination material is absorbed on the contact pad and on the passivation layer. This micro-contamination can cause overkill issue during circuit probing (CP test). The micro-contamination material is removed by an argon sputtering process in this invention. The overkill issue of CP test could be eliminated by adding in this physical clean.

Description

1220170 I Case No. 91117854 丨 a Λ Revision V. Description of the invention α) Yu Fa This invention relates to a kind of wafer electrical pin test, and in particular to a kind of wafer electric property that can improve the accuracy of wafer electric test. In today's information-exploded society, acupuncture is used in electronic products in daily life. No matter in food, clothing, living, and entertainment, products made of integrated circuit components are used. As electronic technology continues to evolve, more functional and human-friendly products are being introduced. As far as the appearance of electronic products is concerned, they are also designed to be light, thin, short and small. Generally speaking, before the electronic product is shipped or before the next step, the electrical performance of the electronic product is checked first to find out the defective product for remedy. Generally, the fuse can be blown to remedy the problem. Good quality. Figures 1 to 3 show enlarged cross-sectional views of a conventional method for detecting a wafer by touching a contact on a wafer with a stylus. Please refer to FIG. 1 first. A wafer 110 is provided first. The wafer 110 has an active surface 1 12. The wafer 110 also includes a protective layer 1 1 4 and a plurality of contacts 1 1 6 (Only one of them is shown), are evenly located on the active surface 1 1 2 of the wafer 1 1 0, and the protective layer 1 1 4 also has multiple openings 1 1 8 (only one of them is shown) to expose Contact 1 1 6. When the wafer 1 1 0 often has a small amount of chemicals (contaminants) 1 2 0 adsorbed on the contact 1 1 6 during the manufacturing process, this pollutant 1 2 0 may also cover the wafer 1 1 0 Protective layer 1 1 4 and contacts 1 1 6. Please refer to FIG. 2. After the wafer 1 110 is manufactured, an electrical inspection step must be performed. It can use multiple probes 1 3 0 (only one of which is shown) to touch the contact point 1. 16. Connect the stylus probe 1 3 0 to the contact 1 1 6 electrically to test the electrical performance of the wafer 1 1 0. When the stylus probe 1 3 0 touches the contact point

9656twf1.ptc Page 7 1220170 _ Case No. 91117854 丨 v: Two V: Month correction _ V. Description of the invention (2) /: '' When 1 1 6, the pollutant 1 2 0 will stick to the stylus probe 1 3 0 In severe cases, even the test results of the stylus probe 130 will be affected. Please refer to Figure 3. After the electrical test step is completed, the stylus probe 1 3 0 will be lifted. However, during the lifting process, the pollutant 1 2 0 and the metal substance 1 on the surface of the contact 1 1 6 17 will also be brought up and stuck to the stylus probe 130. As described above, after the needle tester 130 has repeatedly repeated the electrical detection steps, a very thick layer of pollutants will accumulate on the surface of the needle tester 130 that is in contact with the contacts. When the stylus tester 130 tests the contacts on another wafer, it will be affected by the contaminants accumulated on the stylus tester 130 during the previous electrical test process, and the judgment will be wrong. For example, due to the influence of the pollutants accumulated on the needle tester 130, a disconnection occurs between the needle tester 130 and the contact 116. Therefore, the accuracy of the electrical test results of wafers is very low using the wafer electrical test methods described above. Therefore, the object of the present invention is to provide a method for measuring the electrical needle of a wafer, which can improve the accuracy of the electrical detection of the wafer. Before describing the present invention, the usage of the spatial preposition is defined. The so-called spatial preposition π means that the spatial relationship between the two objects is accessible or inaccessible. For example, object A is on object B, which means that object A can be directly disposed on object B, and object A is in contact with object B; or object A is located in the space on object B, A The object is not in contact with the B object. In order to achieve the above and other objectives of the present invention, a method for electrical pin testing of wafers is proposed, which includes at least the following steps. First, a wafer is provided. The wafer has an active surface, and the wafer also has a protective layer and at least one contact, both located on the active surface of the wafer, and the protective layer has at least one opening.

9656twf1.ptc Page 8 1220170 Case number 91117854. % Day, day, amendment 5. Description of the invention (3) ^ a ^ ‘Mouth exposes the contact, and a pollutant covers at least the contact. Next, remove contamination from the contacts. After that, a stylus is used to touch the contacts and electrically connect the contacts to check the electrical performance of the wafer. According to a preferred embodiment of the present invention, the contamination at the contact is removed by a physical splash method using argon atoms, and the stylus is, for example, a probe. The material of the protective layer may be an inorganic compound or an organic compound. In addition, the contact may be a metal pad, and the material of the surface layer may be gold or aluminum, and the contact may also be a bump, and the material may include gold. In summary, according to the electrical needle measurement method of the present invention, after the wafer fabrication is completed, the contaminants are first removed by a sputter clean method, and then the contact points of the needle detector are touched with a needle. The electrical performance of the wafer is measured, so when the stylus is in contact with the contacts, almost no contaminants will stick to the stylus, so the stylus can accurately measure the electrical performance of the wafer. In addition, even when the stylus is subjected to repeated repeated electrical detection steps, although a very thick layer of metal material accumulates on the surface of the stylus that is in contact with the contacts, this metal material is very conductive because Good material, so when the stylus is used to test the bumps on another wafer, the electrical performance of the other wafer can still be accurately determined. , Features, and advantages can be further combined with the accompanying drawings to make the above and other objects of the present invention obvious and easy to understand. A preferred embodiment 5 is described in detail below: The symbols of the drawings do not explain: 1 1 0 Wafer 1 1 2: Active surface

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Embodiments Figures 4 to 7 show large cross-sectional views of a method for detecting a wafer by touching a metal pad on a wafer with a stylus according to a first preferred embodiment of the present invention. Please refer to FIG. 4 first. A wafer 210 is provided. The wafer 210 has an active surface 212. The wafer 210 also includes a protective layer and multiple contacts 2 1 6 (only one of which is shown). ), Which are evenly located on the main surface 212 ′ of the wafer 2, and the protective layer 214 also has a plurality of openings 2i8 (only one of which is shown at the end) to expose the contacts 216. The material of the protective layer 214 may be of good quality. / Inorganic compounds, such as oxygen silicon compounds, nitrogen silicon, and "(BPSG)", are made of the above materials: If it is polyimide, the second is an organic compound, which is more in the form of a pad ' The form of 3f216 on the surface of the metal pad 216 is, for example, a metal circle 210. In the process of weaving, there are often 3 shells that can be inscriptions or gold. When the crystals are adsorbed on the contacts 2 丨 6, this is a chemical product in the vengeance ( Contaminants) on the protective layer 214 of 2 2 0 and the metal substrate 2 ′ ^. 22D may also cover the wafer 210. The wafer 210 may be advanced before the step of wafer 210 fabrication inspection, and It is necessary to perform an electrical process, such as using a splash method, to remove the pollutants 2 2 0, than to remove the pollutants. , On the atomic layer ^ 14 and on the metal 塾 216 as shown in Figure 5. For example, it is an argon atom, and the formation is as shown in Figure 1 (refer to Figure 6, then one of the tools can be touched) 2丨 6 Use multiple styluses 2 3 0 (only for illustrative connection 'to detect the electricity of the wafer 210 to make the stylus 2 3 0 and the metal pad 216 electrically disabled, of which the stylus 2 3 0 such as

1220170 _ Case No. 91117854. Month Day __ 5. Description of the invention (6) is a probe. Since most of the pollutants 2 2 0 deposited on the protective layer 2 1 4 and the metal pad 2 1 6 have been removed by a splash method, the probe 2 3 0 is in contact with the metal pad 2 1 At 6 o'clock, almost no contaminant 2 2 0 will stick to the stylus 2 3 0, so the stylus 2 3 0 can accurately detect the electrical performance of the wafer 2 1 0. Please refer to Figure 7. After the electrical test step is completed, the stylus sensor 2 3 0 will be lifted. During the lifting process, the metal substance 2 1 7 located on the surface of metal 塾 216 will be brought up and adhered to Stylus on 2 3 0. Even after the stylus tester 230 has repeatedly repeated the steps of electrical detection, although a very thick layer of metal material accumulates on the surface of the stylus tester 230 and the metal pad 216, since this metal substance is A very conductive material, so when the stylus tester 230 is used to test the metal pad on another wafer, the electrical performance of the other wafer can still be accurately determined. In the above-mentioned wafer electrical needle measurement method, the 'needling system touches the metal cymbal and is electrically connected to the metal pad. It uses the metal cymbal as the external contact point of the wafer. However, the application of the present invention is not limited to the above. Applications. The bumps can also be used as external contacts of the wafer, as described below. Please refer to FIG. 8 to FIG. 11, which are enlarged schematic cross-sectional views of a method for detecting a wafer by touching a bump on a wafer with a stylus according to a second preferred embodiment of the present invention. Please refer to FIG. 8 first. A wafer 3 1 0 is provided. The wafer 3 1 0 includes a protective layer 3 1 4 and a plurality of metal pads 3 1 6 (only one of which is shown). The protective layer 314 The configuration and material of the metal pad 316 are as described in the first preferred embodiment, and will not be repeated here. In this embodiment, the wafer also has a plurality of bumps 3 1 9 (only one of which is shown), which are arranged at

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Case No. 9111785j_ V. Description of the invention (7) On the metal pad 316, it is recognized as a wafer. When the wafer 3 1 0 is completed, and the material of the bump 3 1 9 contains a large amount of suspended particles in the air, the wafer 3 1 0 is exposed to the protective layer 314 of the circle 310 and the convex The suspension of Q oxygen and / or particles will be deposited on the protective layer 314 and the bump 319 of the crystal cover wafer 310: this pollutant 3 2 0 will be covered by the detection + the next one will be round 3 7 After the production is completed, an electrical process such as the use of thorium 2 2 I is required to perform the process of removing pollutants 3 2 0 first. The atom struck by V is, for example, a gas atom, and it is ^ Yimingmai according to Figure 10, and then you can use multiple probes 3 3 0 (only draw = one of eight) to touch the bump 3 1 9. The pin tester 3 3 0 is electrically connected to the bumps 3 9 and 9 to test the electrical performance of the wafer 310, and the pin tester 33 0 is, for example, a pin. Since most of the contamination 3 2 〇 deposited on the protective layer / • ^ and the bump 3 1 9 has been removed by sputtering, when the probe 3 3 0 1 contacts the bump 319 , Almost no contaminants 32 will stick to the stylus 3 can 30. Therefore, the stylus probe 33 can accurately pin the electrical performance of the wafer 31 °. Refer to Figure 11, after the electrical test just completed, the process of lifting the stylus 330 330_, A metal object 3 17 located on the surface of the bump 319 is brought up and adhered to the stylus 3 3 0. Even after acupuncture cry 330 has repeatedly repeated the steps of electrical detection, although the surface of the stylus 33 ^ contacting the bump 319 will accumulate-a very thick layer of metal material, but because it is a material system Because it is a highly conductive material, it should be reused.

1220170, daily it Π: year "Amendment Case No. 91117854 丨 V. Description of the Invention (8) L …… — 一-Stylus probe 3 3 0 can still accurately judge when testing the bump on another wafer Out the electrical performance of another wafer. In summary, according to the electrical pin test method of the present invention, after the wafer fabrication is completed, the sputtering method is used to remove the pollutants before touching the pin tester to detect the electrical power of the wafer. Performance, so when the stylus is in contact with the contact, almost no contaminants will stick to the stylus, so the stylus can accurately detect the electrical performance of the wafer. In addition, even when the stylus is subjected to repeated repeated electrical detection steps, although a very thick layer of metal material will accumulate on the surface of the stylus that is in contact with the contacts, however, because this metal substance is very conductive Good material, so when the stylus is used to test the bumps on another wafer, the electrical performance of the other wafer can still be accurately determined. Although the present invention has been disclosed as above with a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can make some changes and retouch without departing from the spirit and scope of the present invention. The scope of protection of the invention shall be determined by the scope of the attached patent application.

9656twf1.ptc Page 14 1220170 92.12.22, _Case No. 91117854 / everyday__ Schematic description ... ......—— Figures 1 to 3 are enlarged cross-sectional schematic diagrams showing a conventional method of using a stylus to touch a contact on a wafer to detect the wafer. Figures 4 to 7 illustrate enlarged cross-sectional views of a method for detecting a wafer by touching a metal pad on a wafer with a stylus according to the first preferred embodiment of the present invention. Please refer to FIG. 8 to FIG. 11, which are enlarged schematic cross-sectional views of a method for detecting a wafer by touching a bump on a wafer with a stylus according to a second preferred embodiment of the present invention.

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Claims (1)

1220170 _Case No. 91117854 Rev. _ VI. Scope of Patent Application 1. A method for electrical pin testing of wafers, including the following steps: Provide a wafer 'the wafer has an active surface' and the wafer also has a The protective layer and at least one contact are both located on the active surface, and the protective layer has at least one opening to expose the contact, and a small amount of pollutants are adsorbed and covered on the contact; the clearing position is at the The contamination on the contact; and touching the contact with a stylus and electrically connecting the contact to detect the electrical performance of the wafer. 2. The electrical needle test method for a wafer as described in item 1 of the scope of the patent application, wherein the contaminants located on the contact are removed by physical sputtering. 3. The electrical needle test method for a wafer as described in item 2 of the scope of the patent application, wherein the contamination at the contact is removed by physical sputtering using an argon atom. 4. The electrical needle test method for a wafer as described in item 1 of the patent application scope, wherein the needle tester is a probe. 5. The electrical needle test method for a wafer as described in item 1 of the scope of patent application, wherein the material of the protective layer is an inorganic compound. 6. The wafer electrical needle test method according to item 1 of the scope of patent application, wherein the material of the protective layer is an organic compound. 7. The electrical pin test method for a wafer as described in item 1 of the patent application scope, wherein the contact is a metal pad. 8. The electrical needle test method for a wafer as described in item 7 of the scope of the patent application, wherein the material of the surface layer of the metal pad is one selected from the group consisting of gold and aluminum. 9656twf1.ptc Page 16 1220170 Case No. 91117854: Year Amendment VI. Patent application scope L: — — one — — — — J 9. The wafer electrical needle described in item 1 of the patent application scope Testing method, wherein the contact is a bump. 10. The wafer electrical needle test method according to item 9 of the scope of the patent application, wherein the material of the bump includes gold. 1 1. An electrical detection method, comprising the steps of: providing a contact, and a pollutant covering the contact; physically removing the pollutant at the contact by a physical splash; and using a The stylus touches the contact and is electrically connected to the contact. 12. The electrical detection method as described in item 11 of the scope of the patent application, wherein the contamination at the contact is removed by physical sputtering using an argon atom. 1 3. The electrical detection method as described in item 11 of the scope of patent application, wherein the stylus is a probe. 14. The electrical detection method as described in item 11 of the scope of patent application, wherein the contact is a metal pad. 15. The electrical detection method as described in item 14 of the scope of patent application, wherein the material of the surface layer of the metal pad is a material selected from the group consisting of gold and aluminum 16. 11. The electrical detection method according to item 11, wherein the contact is a bump. 1 7. The electrical detection method as described in item 16 of the scope of patent application, wherein the material of the bump includes gold. 1 8. — A method of electrical detection, including the following steps: 9656twf1.ptc Page 17 1220170 '09 99; _Case No. 91117854 _ ~ ¥ January Day Amendment _... 4 6. Scope of Patent Application .... Provide A contact, and a pollutant covers the contact; removing the pollutant located on the contact; and touching the contact with a stylus, and electrically connecting the contact. 19. The electrical detection method as described in item 18 of the scope of patent application, wherein the stylus is a probe. 20. The electrical detection method as described in item 18 of the scope of patent application, wherein the contact is a metal pad. 2 1. The electrical detection method as described in item 20 of the scope of patent application, wherein the material of the surface layer of the metal pad is one selected from the group consisting of gold and aluminum. 2 2. The electrical detection method as described in item 18 of the scope of patent application, wherein the contact is a bump. 2 3. The electrical detection method as described in item 22 of the scope of patent application, wherein the material of the bump includes gold. 9656twf1.ptc Page 18