JP3335214B2 - Semiconductor element inspection method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for inspecting a semiconductor device, and more particularly to an improvement in the inspection efficiency.

[0002]

2. Description of the Related Art FIG. 8 shows a conventional semiconductor device inspection method. In this inspection method, probes 41 and 43, a measurement circuit 46, and an inspection stage 50 are used. The probes 41 and 43 are connected to a measurement circuit 46. Measurement circuit 4
Reference numeral 6 gives a predetermined condition to each semiconductor chip 3 and measures its characteristics.

The semiconductor chip 3 has an electrode 28 on the surface and an electrode 29 on the bottom. On the inspection stage 50, the semiconductor chip 3 is energized by bringing the probe 41 into contact with the electrode 28 and the probe 42 with the electrode 29. Next, the characteristics of the semiconductor chip 3 when the current or the like passing through the semiconductor chip 3 is changed by the measuring circuit 46 are measured.

Conventionally, a semiconductor element has been inspected by such an inspection method.

Incidentally, a dry etching method is known as a technique for etching a semiconductor element on a semiconductor substrate having a high integration density. FIG. 9 shows an example of this conventional dry etching method. The semiconductor substrate 2 includes
An element formation region is formed on the entire surface. A desired resist pattern is formed on the surface of the semiconductor substrate 2, and a surface (etched surface) 10 on which the resist 4 is not applied and a surface (mask surface) 14 on which the resist is applied are provided. FIG. 10 is a partial perspective view of FIG.

First, a high energy argon ion beam 8 is generated, and the argon ion beam 8 collides with the entire surface of the semiconductor substrate 2 at a predetermined angle.

On the etching surface 10, the argon ion beam 8 collides with the atoms 6 in the element formation region 36,
The atoms 6 fly out of the semiconductor substrate 2. Then, the atoms 6 are successively ejected by the argon ion beam 8, and the atoms 6 are stripped to the bottom surface 12 of the etching surface. On the other hand, the mask surface 14 is protected by the resist 4 and is not etched. That is,
The semiconductor substrate 2 is etched according to a desired resist pattern. Thereafter, the resist 4 is removed by an alkaline aqueous solution or the like.

Incidentally, in some semiconductor elements, the etched cross section is required to have a mirror surface. As shown in FIG. 11A, for example, in the semiconductor laser device 5, the light emitting section 27 (within several μm from the substrate surface)
Since the laser emitted from is reciprocated many times in both etching cross sections, its emission output is obtained,
In particular, the end face of the light emitting section 27 is required to have a mirror surface.

[0009] The dry etching method has not been used for the semiconductor laser device 5 requiring such a mirror surface because of the following problems.

As shown in FIG. 12, it is difficult to form the end face of the resist 4 without unevenness (101 in the figure) in the masking operation. Therefore, when the argon ion beam 8 collides with the resist 4, at the end face of the resist 4,
Since the light is incident along the irregularities, the etched cross section 16
(FIG. 103) is transferred as it is. Also, in the case where foreign matter is included in the resist 4, irregularities are similarly transferred to the etched cross section 16.

Conventionally, when the reflection surface of the semiconductor laser element 5 is formed, for example, as shown in FIG. 11B, the surface of the semiconductor substrate 2 is cut at predetermined intervals by glass cutting.
After that, a bending stress such as a roller is applied to the semiconductor substrate 2 so that the semiconductor substrate 2 is broken in a direction in which the semiconductor substrate 2 is easily broken, and the mirror surface of the fractured surface 26 is obtained.

[0012]

However, the conventional method for inspecting a semiconductor device has the following problems.

As described above, in the inspection stage, each semiconductor element is in a disjointed state, and it is necessary to arrange each semiconductor element in a predetermined direction and contact the prog, so that the inspection work is complicated and the inspection takes time. There was a problem.

In particular, in the case of the semiconductor laser chip 5 which requires mirror surface properties, especially before the inspection,
In each case, it is necessary to apply a protective coating to the fractured surface 26, so that there has been a problem that it is more complicated. Further, the semiconductor laser chip 5 is required to be as small as possible. However, the cutting method using pressure as described above has a problem that there is a limit to miniaturization of the chip.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and to provide a method for inspecting a semiconductor element which can easily and quickly inspect the semiconductor element.

[0016]

(1) In the method of inspecting a semiconductor device according to the present invention, directional particles are made to collide with a semiconductor substrate, and an etching surface excluding a mask surface is formed in an element forming region of each semiconductor device. After etching deeper and removing the resist of each semiconductor element, one electrode is connected to the semiconductor substrate, and the other electrode is connected to each semiconductor element, and the electrical characteristics of each semiconductor element are inspected. It is characterized by: Further, the etching method of the present invention includes the steps of:
The shape of the protrusion on the end face of the strike is the same as
So that it is not transferred to the etched section
And make the etched cross section a mirror surface
In order to achieve the above, the etching just below the convex portion of the resist end surface
The ion beam is set so that the ion beam is also incident on the cross section.
It is characterized in that the incident angle of the system is changed .

(2) In the etching method according to the present invention, the etching cross section is determined by the direction of incidence of the ion beam.
Characterized by being inclined at a predetermined angle with respect to the direction.

[0018]

(1) In the method of inspecting a semiconductor device according to the present invention, the etching is performed by etching the etched surface of the semiconductor substrate deeper than the device forming region of the semiconductor device so that each semiconductor device is electrically separated. . Therefore, each semiconductor element can be inspected on the semiconductor substrate. Also,
In the method for inspecting a semiconductor device according to the present invention, the shape of the convex portion of the resist end surface is set to be immediately before the convex portion at the time of etching.
Do not transfer to the etched section that appears due to the etching
And the etched cross section will be a mirror surface
In order to avoid this, the edge just below the projection on the end face of the resist
So that the ion beam is also incident on the
The incident angle of the on-beam is changed . Therefore, even when convex shape on the resist end face, the convex
A convex portion is not transferred to the etched cross section immediately below the portion, and a semiconductor element requiring mirror surface property can be inspected on a semiconductor substrate.

(2) In the etching method according to the present invention, the etching cross section may be formed in a direction in which the ion beam is incident.
Characterized by being inclined at a predetermined angle with respect to the direction. Thereby, the etched cross section is
It can be formed perpendicular to the surface of the semiconductor substrate and in a mirror surface .

[0020]

FIG. 1 shows a method of inspecting a semiconductor device 7 according to an embodiment of the present invention. The method includes a probe 42, a measurement circuit 46, an inspection stage 50, as shown in FIG.
Is used. Each semiconductor element is inspected for its electrical characteristics by being energized on the inspection stage 50. At this time, the semiconductor element 7 has been etched by the directional particles on the semiconductor substrate 2 as follows.

The etched surface 23 of the semiconductor substrate 2 corresponds to FIG.
As shown in FIG. 2B, the etching is deeper than the element forming region 18 of the semiconductor element 7. Thereby, the semiconductor element 7
In a state of being separate from the first element forming region 18 ₁ and the semiconductor element 7 _second element forming region 18 _2. That is, the semiconductor elements 7 are on the semiconductor substrate 2 and are electrically separated from each other. In this state, the electrode 2 is placed on the surface of the semiconductor element 7.
1 is provided with an electrode 22 on the bottom of the semiconductor substrate 2.

Next, the semiconductor substrate 2 is placed on the inspection stage 50.
On top of. The electrode 22 is connected to the measurement circuit 46 via the inspection stage 50. The probe 42 is a measuring circuit 4
6 is connected. When the probe 42 is contacted to the electrode 21 ₁ of the semiconductor element _71, the semiconductor element ₇₁ is energized. Next, the measurement circuit 46, the change of the semiconductor device ₇₁ of the characteristics when changing the current is measured.
Thus, the characteristics of the semiconductor device ₇₁ is tested. next,
Probe 42 is brought into contact with the electrode 21 ₂ of the semiconductor element 7 _2, likewise characteristic of the semiconductor element 7 ₂ is examined. Thus, the semiconductor elements 7 are respectively inspected on the semiconductor substrate 2. As a result, the probe 42 is connected to each semiconductor element 7 in comparison with the case where the semiconductor chip is inspected in a separated state.
Each semiconductor element 7 can be inspected only by making contact with the electrode 21 of the above, and the inspection efficiency is improved. Thereafter, each semiconductor element 7 is separated by dicing to obtain a product.

Next, a method of inspecting a semiconductor device (for example, a semiconductor laser device) in a case where the mirror surface of the etched section is required will be described.

FIG. 2 shows a method of inspecting a semiconductor laser device 5 according to one embodiment of the present invention. In this method, FIG.
As shown in FIG.
A probe guide 44, a measurement circuit 46, a light shielding device 48, and an inspection stage 50 having the same 2 are used.

The semiconductor laser device 5 on the semiconductor substrate 2
The element formation region 36 (FIG. 2B) is dry-etched by the following method, and is sent to the inspection stage 50.

FIG. 3 shows a method of dry-etching the semiconductor substrate 2 according to one embodiment of the present invention. An element formation region 36 is formed on the entire surface of the semiconductor substrate 2. In the x direction, a plurality of etched surfaces 10 (10 ₁ , 10 ₂ ,
10 _3, a plurality of mask surfaces 14 ...) and the resist 4 is applied (14 _1, 14 _2, 14 _3, ...) are provided alternately. The semiconductor substrate 2 rotates in the P and Q directions about a rotation axis J located in the x direction and substantially at the center of the semiconductor substrate 2 in the y direction.

When the ion beam, which is a directional particle, collides with the semiconductor substrate 2, the etching surface 10 excluding the mask surface 14 is etched. FIG. 4 shows a partial perspective view of FIG. FIG. 4A shows a state before etching, and FIG. 4B shows a state after etching by this dry etching method. As shown in Figure 4a, for example, unevenness is generated on the end surface of the resist 4 ₃ of the semiconductor laser device 5 _3.

FIG. 5 is a sectional view of the boundary between the etching surface 10 and the mask surface 14 in FIG. As shown in this figure, the resist 4 (4 ₁ , 4 ₂ , 4 ₃ ,...) Of the semiconductor laser element 5 is used.
The end face and the etched section 16 (16 ₁ , 16 ₂ , 16 ₃ ,
・ ・) Is displayed.

First, the ion beam is applied to the etching section 16.
It is incident substantially parallel to, in Figure 4a, the semiconductor laser element ₃ of the etched surface ₁₀₃ and collide with the resist 4 _3. The incident angle of the ion beam is substantially perpendicular to the rotation axis J.

As shown in FIG. 5, the semiconductor substrate 2, the incident angle P about the axis of rotation J, because it is rotatable Q direction, in the etching section 16 _3, the semiconductor substrate 2 of the ion beam Changes from α ゜ to γ ゜.
In this example, the angle of incidence is in the range of about 45 ° to 135 °.

[0031] Therefore, the ion beam strikes while changing the incident angle be substantially parallel to the etching section 16 _3. Thus, the ion beam, since the around to the etching section 16 ₃ immediately under the resist 4 ₃ end surfaces, even if there is unevenness on the resist 4 ₃ end surfaces, etch profile 16 _3, the etching state is not uneven as shown in Figure 4b Is done. Thus the etching section 16 ₃ is a mirror. The resist 4 ₃ left is removed by an alkaline aqueous solution.

As described above, according to the dry etching method, the unevenness of the etched section 16 due to the transfer of the unevenness of the resist end face is not generated conventionally.
Mirror surface is realized.

When the ion beam collides with the resist 4, the end face is etched and the end face of the resist 4 recedes as shown in FIG. As a result, the etched section 16 may be inclined at an angle θ °. Therefore, when verticality of the etched section 16 is required, as shown in FIG. 6B, the etched section 16 is tilted by θ ° in advance. Thereby, the etching section 16 is vertically etched.
In order to make the etched section 16 a mirror surface,
As shown in FIG. 6c, the center of the rotation axis G inclined at the angle θ ° is the center of the etching cross section 16 inclined at the angle θ °.
It is necessary to change the angle of incidence of the ion beam in the V and W directions.

Here, returning to FIG. 2, the etched surface 12 of the semiconductor substrate 2 is etched deeper than the element forming region 36 of the semiconductor laser element 5, as shown in FIG. 2B.
Thus, the element formation region 36 ₃ of the semiconductor laser device 5 ₃
And in a state of being separated from the element formation region 36 ₁₃ of the semiconductor laser device 51 _3. Similarly, the element formation region 36 ₀₃ both separated state of the semiconductor laser device 5 ₃ element forming region 36 ₃ and the semiconductor laser element 5 _03. However, the semiconductor laser element ₃ itself has not been separated from the semiconductor substrate 2. In this state, the semiconductor laser element ₃ surface electrodes 33 to ₃ of the electrode 34 is provided at the bottom of the semiconductor substrate 2.

Next, the semiconductor substrate 2 is placed on the inspection stage 50 which is shielded from light by the light shielding device 48. The electrode 34 is connected to a measurement circuit 46 via an inspection stage 50. The probe 42 is connected to a measuring circuit 46. When the probe 42 is brought into contact with the electrode 33 ₃ of the semiconductor laser element _3, the semiconductor laser element ₃ is energized, the laser is emitted from the light emitting unit 27 _3. next,
In a state with its photodiode 40 to the light emitting portion 27 _3,
The measuring circuit 46, the intensity change of the scattered light of the laser is measured at the time of changing the current through the semiconductor laser device 5 _3. Thus, the characteristics of the semiconductor laser element ₃ is examined. Next, the probe 42 is connected to the semiconductor laser element 5 ₁₃
Brought into contact with the electrodes 33 _13, likewise the semiconductor laser element 5
_Thirteen properties are tested. As described above, each semiconductor laser element 5 is inspected on the semiconductor substrate 2, and the inspection efficiency is improved as compared with the conventional inspection method. After that, each semiconductor laser element 5 is separated by dicing into a product.

The method of inspecting a semiconductor device is described in FIG.
Etch profile 60 (60 as shown in _1, 60 _2, 60
₃ , 60 ₄ ) can also be used when inspecting an optical component 9 in which the mirror surface is required and the angle of the etched section 60 is, for example, 45 °. In this case, the optical component 9 is etched by the following dry etching method.

[0037] For example, in the etching section 60 _1, by rotating the optical component 9 in the etching section 60 within ₁ about a rotation axis K of the same angle as the etching section 60 _1, the resist 64 etched under an end cross-sectional 6
0 ₁ the ion beam is impinging. As a result, the etched section 601 can be made a mirror surface even if the end face of the resist 64 has irregularities. Similarly, by rotating the optical component 9 about the rotation axes L, M, and N, the etched sections 60 ₂ , 60 ₃ , and 604 can be mirror-finished.

In this embodiment, when etching the semiconductor substrate, the incident angle of the ion beam is changed by rotating the semiconductor substrate, but the incident angle of the ion beam itself is changed without rotating the semiconductor substrate. You may make it change.

The particles of the present invention may be an ion beam, an atomic beam, a plasma particle, a molecular beam, or the like.
E, dry etching method such as ion milling, CA
It is also applicable to IBE (Chemical Assist Ion Beam Etching) and the like.

[0040]

According to the method for inspecting a semiconductor device of the present invention, the etching is performed by etching the etched surface of the semiconductor substrate deeper than the device forming region of the semiconductor device so that each semiconductor device is electrically separated. Therefore, each semiconductor element can be inspected on the semiconductor substrate. Thus, it is possible to provide a method for inspecting a semiconductor element that easily and quickly inspects the semiconductor element. A method of inspecting a semiconductor device of the present invention, further, when etching, convex resist end face
The shape of the part appears due to the etching just below the convex part
Not transferred to the etched cross section
In order to make the etched section mirror-finished,
Ion is also applied to the etched section just below the convex part of the dist end face.
Incident angle of the ion beam so that the beam is incident
I am going to change it . Therefore, the resist end face
Even if there is a convex shape , the etched cross section just below the convex portion
The semiconductor element that does not transfer the shape of the projection to the mirror and requires mirror-likeness can be inspected on the semiconductor substrate.

(2) In the etching method according to the present invention, the etching cross section may be determined by a direction of incidence of the ion beam.
It is in a state inclined at a predetermined angle with respect to the direction. Therefore, the etched cross section can be formed perpendicular to the surface of the semiconductor substrate and mirror-finished.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a method of inspecting a semiconductor device according to an embodiment of the present invention.

FIG. 2 is a diagram showing a method of inspecting a semiconductor laser device according to one embodiment of the present invention.

FIG. 3 is a view showing a dry etching method for a semiconductor substrate according to one embodiment of the present invention;

FIG. 4 is a partial perspective view showing a dry etching method for a semiconductor substrate according to one embodiment of the present invention;

FIG. 5 shows a cross-sectional view of the above-described dry etching method for a semiconductor substrate.

FIG. 6 is a diagram illustrating correction of vertical etching.

FIG. 7 is a view showing a dry etching method for an optical component according to another embodiment.

FIG. 8 is a diagram showing a conventional method for inspecting a semiconductor device.

FIG. 9 is a diagram showing a conventional dry etching method.

FIG. 10 is a partial perspective view of a conventional dry etching method.

FIG. 11 is a view showing a conventional method for obtaining mirror-likeness by breaking.

FIG. 12 is a perspective view showing unevenness of an etching cross section in a conventional dry etching method.

[Explanation of symbols]

 2 Semiconductor substrate 7 Semiconductor element 18 Element formation area 23 Etching surface 42 Probe 46 Measurement circuit 50 Inspection stage

Claims (2)

(57) [Claims] 1. A semiconductor substrate, comprising: colliding directional particles with a semiconductor substrate, etching an etching surface excluding a mask surface deeper than a device forming region of each semiconductor device, and removing a resist of each semiconductor device; One electrode is connected to each other, and the other electrode is connected to each semiconductor element,
Inspecting the electrical characteristics of each semiconductor element, wherein the etching method is such that the shape of the convex portion on the resist end face is the same as that of the edge immediately below the convex portion.
Not transferred to the etched cross-section
And make the etched cross section a mirror surface.
Therefore, the etching cross section immediately below the convex portion of the resist end face is also required.
Injection of the ion beam as if it were incident
A method for inspecting a semiconductor device , comprising changing an angle . 2. The etching method according to claim 1, wherein the etching section is inclined at a predetermined angle with respect to an incident direction of the ion beam.
A method for inspecting a semiconductor element.