Abstract:
A method for manufacturing a cantilever structure of a probe card is disclosed. In accordance with the method of the present invention, a first sacrificial wafer is used as a mold to form a cantilever structure having various shapes, a microscopic pitch and a high aspect ratio. In accordance with the method of the present invention, a probe tip may be formed by using a second sacrificial substrate and a bonding.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a method for manufacturing a cantilever structure of a probe card, and more particularly to a method for manufacturing a cantilever structure of a probe card wherein a silicon wafer is used as a mold to form a cantilever structure having various shapes, a microscopic pitch and a high aspect ratio. 
     2. Description of the Related Art 
     Generally, one or more dies are formed on a wafer. A wafer-level test should be carried out to find out that the one or more dies are not defective. The wafer-level test is carried out using a probe card having a plurality of cantilever structure having a probe beam, a tip and a bump. The cantilever structures contact a plurality of pads formed on the wafer, and relays a test signal from a tester to the plurality of pads to carry out the test. 
     As a size of a semiconductor device is reduced, a pitch of the pads is also reduced. Therefore, a distance between the probe tips for carrying out the test by contacting the pads is also drastically reduced. In addition, a number of the probe tips are drastically increased in order to test a large number of dies per test. 
     Therefore, a need for a probe card including a cantilever structure having various pitched and shapes is increasing. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a method for manufacturing a cantilever structure of a probe card wherein a silicon wafer is used as a mold to form a cantilever structure having various shapes, a microscopic pitch and a high aspect ratio. 
     In accordance with the present invention, there is provided a method for manufacturing a cantilever structure, comprising steps of: (a) forming a first mask layer pattern defining a probe beam region and a second mask layer pattern defining a bump on first and second surfaces of a first sacrificial substrate, respectively; (b) etching the first sacrificial substrate exposed by the first mask layer pattern and the second mask layer pattern to form the probe beam region and the bump region mutually connected; (c) removing the first mask layer pattern and the second mask layer pattern; (d) bonding the first sacrificial substrate including the probe beam region and the bump region to an insulating substrate; (e) forming a cantilever structure filling the probe beam region and the bump region; and (f) removing the first sacrificial substrate. 
     The method in accordance with the present invention may further comprise forming an oxide film on a surface of the first sacrificial substrate after carrying out the step (c). 
     The method in accordance with the present invention may further comprise forming a first bonding layer between the first sacrificial substrate and the insulating substrate. 
     The method in accordance with the present invention may further comprise forming a probe tip at an end portion of the cantilever structure. 
     Preferably, the probe tip formation step comprises: forming a third mask layer pattern exposing a probe tip region of the cantilever structure is formed; forming the probe tip in the probe tip region; and removing the third mask layer pattern. 
     Preferably, the probe tip formation step comprises: forming a fourth mask layer pattern exposing a portion of a second sacrificial substrate corresponding to a probe tip region of the cantilever structure is formed on the second sacrificial substrate; etching the second sacrificial substrate using the fourth mask layer pattern as a mask to form the probe tip region; forming the probe tip in the probe tip region; forming a fifth mask layer pattern exposing the probe tip and an adjacent region; forming a second bonding layer in a region exposed by the fifth mask layer pattern; removing the fifth mask layer pattern; bonding the second bonding layer to the probe tip region of the cantilever structure; and removing the second sacrificial substrate. 
     It is preferable that each of the first mask layer pattern and the second mask layer pattern comprises a TEOS film. 
     It is also preferable that the first bonding layer comprises a photoresist film. 
     Preferably, the insulating substrate comprises one of a ceramic substrate, a glass substrate, an insulating silicon substrate and combinations thereof. 
     Preferably, the step (e) comprises an electroplating process. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS. 1   a  through  1   i  are cross-sectional views illustrating a method for manufacturing a cantilever structure of a probe card in accordance with a first embodiment of the present invention. 
         FIGS. 2   a  through  2   l  are plane and cross-sectional views illustrating a method for manufacturing a cantilever structure of a probe card in accordance with a second embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention will now be described in detail with reference to the accompanied drawings. The interpretations of the terms and wordings used in Description and Claims should not be limited to common or literal meanings. The embodiments of the present invention are provided to describe the present invention more thoroughly for those skilled in the art. 
       FIGS. 1   a  through  1   i  are cross-sectional views illustrating a method for manufacturing a cantilever structure of a probe card in accordance with a first embodiment of the present invention. 
     Referring to  FIG. 1   a , first and second mask layers (not shown) are formed on first and second surface of a first sacrificial substrate  100 , respectively. It is preferable that the first and second mask layers comprise a photoresist film or a TEOS film. 
     Thereafter, a first mask layer pattern  100   a  defining a probe beam region  120  and a second mask layer pattern  100   b  defining a bump are formed on the first surface and the second surface of the first sacrificial substrate  100 , respectively via a photolithography and etching process. 
     Referring to  FIG. 1   b , the first sacrificial substrate  100  exposed by the first mask layer pattern  100   a  and the second mask layer pattern  100   b  are etched to form the probe beam region  120  and the bump region  130 . As shown in  FIG. 1   b , the first surface and the second surface of the first sacrificial substrate  100  is subjected to a deep etching so that the probe beam region  120  and the bump region  130  formed on opposite sides are mutually connected. 
     Thereafter, the first mask layer pattern  100   a  and the second mask layer pattern  100   b  are removed to expose the surfaces of the first sacrificial substrate  100 . 
     Referring to  FIG. 1   c , the surfaces of the first sacrificial substrate  100  is oxidized to form an oxide film  140 . 
     Referring to  FIG. 1   d , a first bonding layer  150  is formed on the second surface of the first sacrificial substrate  100 . The first bonding layer  150  facilitates a bonding of the first sacrificial substrate  100  and an insulating substrate  160 . It is preferable that the first bonding layer  150  comprises a photoresist film. 
     Thereafter, the first sacrificial substrate  100  including the probe beam region  120  and the bump region  130  is bonded to the insulating substrate  160 . It preferable that the insulating substrate  160  comprises one of a ceramic substrate, a glass substrate, an insulating silicon substrate and combinations thereof. 
     Referring to  FIGS. 1   e  and  1   f , a cantilever structure  170  filling the probe beam region  120  and the bump region  130  is formed. It is preferable that the cantilever structure  170  is formed via electroplating process. 
     Referring to  FIG. 1   g , a third mask layer (not shown) is formed on an exposed portion of the cantilever structure  170  and the first sacrificial substrate  100 . Thereafter, the third mask layer is selectively etched to form a third mask layer pattern  180  exposing a probe tip region of the cantilever structure  170  disposed at an end portion of the cantilever structure  170 . The probe tip  190  is then formed in the probe tip region. 
     Referring to  FIG. 1   h , the third mask layer pattern  180  is removed. 
     Referring to  FIG. 1   i , the first sacrificial substrate  100  is removed to complete the formation of the cantilever structure  170 . 
       FIGS. 2   a  through  2   e  are plane and cross-sectional views illustrating a method for manufacturing a cantilever structure of a probe card in accordance with a second embodiment of the present invention. 
     Referring to  FIG. 2   a , first and second mask layers (not shown) are formed on first and second surface of a first sacrificial substrate  100 , respectively. It is preferable that the first and second mask layers comprise a photoresist film or a TEOS film. 
     Thereafter, a first mask layer pattern  100   a  defining a probe beam region  120  and a second mask layer pattern  100   b  defining a bump are formed on the first surface and the second surface of the first sacrificial substrate  100 , respectively via a photolithography and etching process. 
     Referring to  FIG. 2   b , the first sacrificial substrate  100  exposed by the first mask layer pattern  100   a  and the second mask layer pattern  100   b  are etched to form the probe beam region  120  and the bump region  130 . As shown in  FIG. 1   b , the first surface and the second surface of the first sacrificial substrate  100  is subjected to a deep etching so that the probe beam region  120  and the bump region  130  formed on opposite sides are mutually connected. 
     Thereafter, the first mask layer pattern  100   a  and the second mask layer pattern  100   b  are removed to expose the surfaces of the first sacrificial substrate  100 . 
     Referring to  FIG. 2   c , the surfaces of the first sacrificial substrate  100  is oxidized to form an oxide film  140 . 
     Referring to  FIG. 2   d , a first bonding layer  150  is formed on the second surface of the first sacrificial substrate  100 . The first bonding layer  150  facilitates a bonding of the first sacrificial substrate  100  and an insulating substrate  160 . It is preferable that the first bonding layer  150  comprises a photoresist film. 
     Thereafter, the first sacrificial substrate  100  including the probe beam region  120  and the bump region  130  is bonded to the insulating substrate  160 . It preferable that the insulating substrate  160  comprises one of a ceramic substrate, a glass substrate, an insulating silicon substrate and combinations thereof. 
     Referring to  FIGS. 2   e  and  2   f , a cantilever structure  170  filling the probe beam region  120  and the bump region  130  is formed. It is preferable that the cantilever structure  170  is formed via electroplating process. 
     Referring to  FIG. 2   g , a fourth mask layer (not shown) is formed on a second sacrificial substrate  200 . Thereafter, the fourth mask layer is selectively etched to form a fourth mask layer pattern  220  exposing a portion of the second sacrificial substrate  200  corresponding to a probe tip region  210  of the cantilever structure  170  disposed at an end portion of the cantilever structure  170 . Thereafter, the second sacrificial substrate  200  is etched using the fourth mask layer pattern  220  as a mask to form the probe tip region  210 . The fourth mask layer pattern  220  is then removed. 
     Referring to  FIG. 2   h , a probe tip  180  filling the probe tip region  210  is formed. 
     Referring to  FIG. 2   i , a fifth mask layer (not shown) is formed on the second sacrificial substrate  200 . Thereafter, the fifth mask layer is selectively etched to form a fifth mask layer pattern  230  exposing the probe tip  180  and an adjacent region. 
     Thereafter, a second bonding layer  240  is formed in a region exposed by the fifth mask layer pattern  230 . 
     Referring to  FIG. 2   j , the fifth mask layer pattern  230  is removed. 
     Referring to  FIG. 2   k , the second bonding layer  240  is bonded to the probe tip region of the cantilever structure  170 . The second sacrificial substrate  200  is then removed to complete the formation of the cantilever structure  170 . 
     As described above,