KR100214162B1 - Manufacture of semiconductor device - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wafer probe card used for probing IC chips integrated on a semiconductor wafer, When a probing test of a semiconductor IC chip is performed by connecting a signal pattern to a silicon micro-tip by manufacturing a wafer probe card having the same properties as a wafer to be inspected having a ball or bar-shaped vertical probe, Provided is a wafer probe card having a vertical probe on top of a microtip which can be simultaneously inspected and which can automate and simplify the process of probing.

Description

Wafer probe card having a vertical probe on top of a microtip and method of manufacturing the same

Figures 1a-1e are cross-sectional views sequentially illustrating the fabrication process for forming a cantilevered tip of a wafer probe card according to the present description;

FIG. 2 is a cross-sectional view of a bumper probe formed on the cantilever tip of FIG. 1e; FIG.

FIG. 3 is a cross-sectional view showing that a ball-type probe is formed on the cantilever tip of FIG.

FIG. 4 is a cross-sectional view of a cantilever tip of FIG.

FIG. 5 is a perspective view of a bumper-type probe formed on a micro bridge type tip according to another embodiment of the present invention; FIG.

FIG. 6 is a device for performing probing inspection of IC chips integrated on a wafer using a conventional probe card.

7a is a plan view of a probe card having a horizontal needle method for performing a conventional wafer probing test.

Figure 7b is a cross-sectional view of the probe card having a horizontal needle system of Figure 7a.

Fig. 8a is a plan view of a membrane type of dot probe card for carrying out another conventional wafer probing test. Fig.

Figure 8b is a cross-sectional view of the membrane type of the dot probe card of Figure 8a.

DESCRIPTION OF REFERENCE NUMERALS

11: n-type silicon substrate 12: n-epi layer

13: n ⁺ diffusion layer 14: micro cantilever tip

15: porous silicon 16: bumper type probe

17: ball probe 18: rod probe

19: Microbridged tip 100: Inspection system

101: Inspection head 102: PCB substrate

102A: probe card 103: wafer

103A: semiconductor IC chip 104: pad

105: Chuck 106: Wafer probe station

107: soldering part 108: horizontal needle

109: Probe 110: Signal pattern

111: Membrane 112: Dot

113: Pressure retaining box cover 114: Pressure maintaining regulator

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a probe card used for probing test of IC chips integrated in a semiconductor wafer and a method of manufacturing the probe card, The present invention relates to a wafer probe card capable of simultaneously inspecting all the IC chips of a wafer and a method of manufacturing the same.

At present, the manufacturing technology of semiconductor integrated circuits is gradually becoming higher and higher, while the size of IC chips is relatively decreased. In order to determine whether such an IC chip is defective, the following two methods of inspection are indispensable.

The first is a wafer inspection method for inspecting an IC chip in a wafer state, and the second is a final test method in which an IC chip of a wafer is manufactured in a package form and then inspected.

FIG. 6 shows a general wafer probing inspection apparatus for use in the above-described wafer probing inspection. Referring to the structure, a test head 101 electrically connected to an inspection system 100 for inspecting an IC chip in a wafer state is shown. The wafer 103 on which the semiconductor IC chip 103A is formed is mounted on the chuck 105 and the chuck 105 is disposed on the wafer probe station 106. [ At this time, the probe card 102A having the horizontal type needles 108 is installed between the inspection head 101 and the wafer. At this time, in order to inspect the defect of the semiconductor IC chip 103A, the pad 104 on the semiconductor IC chip 103A is brought into contact with the horizontal needle 108 mounted on the probe card 102A. The probe card 102A having a horizontal needle is electrically connected to the inspection head 101. [ The inspection system 100 checks whether the semiconductor IC chip 103A is defective through the horizontal needle 108 of the probe card 102A in contact with the pad 104. [

The probe card 102A on which the horizontal needle 108 is mounted is shown in more detail in Figures 7a and 7b.

The horizontal needle 108 is generally 40 to 50 mm long and 200 to 250 占 퐉 thick. At this time, the material of the horizontal needle 108 is a conductive metal, and tungsten is generally used in many cases. Beyllium, Be-Cu or Paliney-7, P-7 may be used in consideration of strength, abrasion resistance and conductivity. Ordinary metals plated with gold or copper may also be used. do.

After the horizontal needle 108 is bent with the above-mentioned material, a probe ring 109 made of an epoxy resin material is formed to fix the horizontal needle 108 to complete the needle module 108 do. Next, the needle module is attached to the PCB substrate of the probe card already manufactured. Next, each needle is soldered to the signal pattern 110 formed on the substrate and fixed. At this time, since the above process must be performed through a microscope, it is very difficult to adjust the length and the fixing position of the needle at the time of manufacturing the needle module.

Further, it is difficult to adjust the bending angle when bending the tips of the needles, and it is difficult to maintain the spacing between the needles when mounting the needles on the signal pattern, It takes a long time and the probability of occurrence of defects increases.

Further, since the length of the needles is long, the frequency characteristics and the impedance control become poor, and the space is limited in the manufacture of the needle module according to the size, arrangement, spacing and position of the pads 104, Since the number of needles to be manufactured is limited, a needle module for inspecting a plurality of chips needs to be stacked with layers of second, third, and fourth needle mounting, so that the length, thickness, and arrangement The control becomes more difficult and the defect rate becomes higher.

Further, in such a laminated structure, it is very difficult to keep the tension control of the needles constant.

Therefore, the pad design position of the semiconductor IC chip is limited due to the above-described problems, and there is a limit to the multi-chip test.

As another conventional technique for solving the above problems, there is a membrane type probe card as shown in Figs. 8A and 8B. The structure of the membrane type probe card basically maintains the structure of the horizontal needle type probe card. However, the portion contacting the pad 104 on the semiconductor IC chip is not a horizontal needle but a dot 112 capable of performing a soft touch. At this time, the tension of the dot 112 is retained by the flexible membrane 111, thereby keeping the contact between the dot 112 and the pad 104 constant.

In order to further facilitate the light contact of the dot 112 on the membrane 111 and to prevent the pad from being damaged, another pressure holding adjuster 114 composed of a pivot spring is used as another tension holding assist device Thereby forming a pressure holding box cover 113. [

The above-mentioned membrane type dot probe card compensated for many drawbacks of the horizontal needle type probe card.

However, since the structure is fundamentally a horizontal type, it still has a problem with the horizontal needle type. That is, since the size of the membrane for maintaining a constant tension is limited, it is difficult to expand the production of a membrane type dot probe card for inspecting a large number of chips. Further, since it is difficult to control the tension of the membrane 111 as a whole, there is another problem that it is possible to partially cause a contact failure each time the dots 112 and the pad come in contact with each other.

In addition, since the length of the dot 112 is not long, there is a problem that the wafer 112 may cause a poor contact between the wafer and the probe card.

In order to solve the problems of the horizontal needle type probe card and the membrane type probe card, according to the patent application No. 25232 filed on August 17, 1995 by the applicant of the present invention, the needle used in the probe card is inserted into the notch And a probe card was manufactured by a method using a scalpel as a whole.

However, the probe card having the vertical needle has a problem that some microscope manual work is required in the manufacturing process like the probe card having the horizontal needle. Further, there is a problem that the burn-in test of the semiconductor IC chip is still difficult as in the case of the probe card having the horizontal type needles.

In order to solve the above problems, the present invention proposes a wafer probe card having various types of silicon micro-tips integrated on a wafer and a vertical probe on the wafer, The probing method can be integrated so that the wafer on which the IC chip is manufactured can be subjected to the wafer probing test and all ICs on the wafer can be inspected. Chip can be inspected at the same time, and the burn-in test can be performed even in the wafer state.

According to an aspect of the present invention, there is provided a semiconductor device comprising: a substrate having a predetermined portion of a semiconductor wafer etched to have a space; a cantilever tip formed on the substrate; and a microtip upper portion having a vertical probe formed on the cantilever- And a vertical probe on the wafer probe card.

The present invention also provides a method of manufacturing a semiconductor device, comprising: a first step of forming an n ⁺ diffusion layer having a predetermined depth on a silicon wafer ^; a second step of forming a cantilevered tip of n-epi on the n ⁺ diffusion layer ^; A fourth step of etching the porous silicon; and a fifth step of forming a vertical probe with a conductive material on the cantilever-type tip, And a method of manufacturing a wafer probe card having a probe.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

Figures 1a-1e illustrate in sequence the basic steps of forming a microcantilever-type tip according to one embodiment of the present invention. Firstly, FIG. 1A shows that an n ⁺ diffusion layer 13 of a certain width and depth is formed on an n-type silicon wafer 11. The manufacturing process of the n-type silicon wafer 11 is similar to that of the n-type silicon wafer 11, Is cleaned with a standard substrate cleaning method. Thereafter, an oxide film (not shown) of about 8000 ANGSTROM is grown on the cleaned n-type silicon wafer 11. Next, a mask pattern is formed with a photoresist to define a region where a silicon micro-tip to be described later is to be formed. After removal of the photo etching process and then the n ⁺ diffusion layer 13, the oxide film of the portion is to be formed on, n ⁺ diffusion layer of about 20㎛ depth in the n-type silicon wafer 11 using POCl ₃ the oxide film is selectively exposed ( 13). Finally, all the oxide film remaining on the silicon wafer 11 is removed. 1b shows the growth of the n-epi 12 to form the cantilevered tip of the microstructure after the process shown in FIG. 1a. Here, the material of the n-epi (12) is silicon and has a resistivity of about 10? 占 cm m and a thickness of about 2 to 10 占 퐉. 1c, a photoresist is coated on the n-epi layer 2, and then a mask pattern having a desired shape is formed by photolithography. Next, the exposed n-epi layer 12 on which the mask pattern is not formed is selectively etched by wet etching or dry etching to expose a predetermined portion of the n ⁺ diffusion layer to form a cantilever tip 14 ). At this time, the shape of the mask may be formed in a bridge shape or other desired shape in addition to the cantilever shape to form the bridge tip 19 as shown in FIG. 1d shows a step of denaturing the n ⁺ diffusion layer 13 shown in Fig. 1c with the porous silicon 15.

That is, the exposed n ⁺ diffusion layer 13 is subjected to an anodic reaction in a high concentration HF solution for a suitable time using a constant voltage or a constant current source to denature the n ⁺ diffusion layer 13 with the porous silicon 15 (PSL) FIG. 1D shows a process of removing the porous silicon 15 shown in Fig. 1D. The n-type silicon wafer 11 having the cantilever tip 14 formed on the porous silicon 15 is placed in a position 5 % NaOH solution or the like to remove the porous silicon 15, thereby forming a cantilever tip 14 of a predetermined size and shape on the n-type silicon wafer 11. Then,

2, a conductive metal (such as Pb or Au) is bonded to a desired portion of the microcantilever tip 14 manufactured by the process shown in FIGS. 1a through 1e through a bump type probe 16, A bimetal probe 16 is formed by depositing a conductive metal on the cantilever tip 16, forming a mask pattern on a portion to be probed, and then performing isotropic etching. Such a probe may be made of a ball 17 as shown in FIG. 3 or a rod 18 as shown in FIG.

At this time, the bumper type, the ball type probe or the rod probe can be manufactured by various known methods.

The shapes of the micro-tips in which the bumpers, balls, and bar probes 16, 17, and 18 are formed are shown in FIG. 5 (b) by forming the mask pattern of FIG. It is possible to manufacture a wafer probe card in which a vertical probe is formed on the bridge-type tip as shown in Fig.

The microcantilever tip manufactured as described above can be manufactured so that the size of each individual probe having the probe matches the size of the semiconductor IC chip PAD to be inspected. Since the material of the wafer probe card is the same material as the semiconductor wafer to be inspected, The physical properties of the water are consistent. Therefore, when the probing test is performed, the wafer to be inspected and the wafer probe card to be inspected are excellent in connection with each other, so that it can be applied to various tests. Moreover, since the manufacturing method uses the existing wafer manufacturing process as it is, Because it can be equipped with a production system, productivity can be improved and production cost can be reduced. Further, the present invention can develop the wafer probing inspection process with complete automation and simplification, and can greatly reduce the test cost in the probing test.

In addition, it is possible to perform a burn-in test of a wafer state which has not been performed in the conventional method, and the total length of signal transmission of the silicon micro-tip can be defined as about 100 탆 or less. It has the advantage of being able to perform probe test on the types and types of devices including devices, and it is manufactured with integrated circuit technology and micromachining technology, so it can be miniaturized and refined to standardize, mass-produce, integrate and reproduce easily and at low price.

In addition, since a micro-tip signal processing circuit can be integrated on the same wafer, a conventional probe card PCB (PCB) substrate is not required. Therefore, there is an advantage of excellent signal-to-noise characteristics.

In addition, the number, size, height, angle, tension force, and shape of the vertical probe to be contacted to each pad can be freely varied and can be controlled automatically. Therefore, an undesirable defect Thereby maximizing the reliability of the contact.

Claims (11)

1. A wafer probe card having a vertical probe on a top of a microtip comprising a substrate having a predetermined portion of a semiconductor wafer etched, a microtip formed on the substrate, and a vertical probe formed on the top of the substrate. 2. The wafer probe card of claim 1, wherein the microtip is a cantilever type. 2. The wafer probe card of claim 1, wherein the microtip is a bridge type. The wafer probe card of claim 1, wherein the probes formed on the microtip are bumper-shaped. 2. The wafer probe card of claim 1, wherein the probes formed on the microtip are ball-shaped. 2. The wafer probe card of claim 1, wherein the probe formed on the microtip is a bar. A second step of forming an n ⁺ diffusion layer of a predetermined depth on a silicon wafer ^; a second step of forming a micro-tip of n-epi on the n ⁺ diffusion layer ^; A fourth step of etching the porous silicon, and a fifth step of forming a vertical probe on the microtip. The method of manufacturing a wafer probe card according to claim 1, The method of manufacturing a wafer probe card according to claim 7, wherein the micro-tip of the second step is manufactured as a cantilever type or a bridge type. 8. The method of claim 7, wherein the probe of the fifth step is manufactured in a bumper shape. 8. The method of claim 7, wherein the probe of the fifth step is formed in a ball shape. The method according to claim 7, wherein the probe of the fifth step is formed in a bar shape.