JP2986008B2 - Voltage distribution observation device, voltage probe, and method of manufacturing voltage probe - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a general-purpose voltage distribution observing apparatus having a high spatial resolution, a voltage probe, and a method of manufacturing a voltage probe. The present invention also relates to a technique that is effective when applied to a technique for confirming the surface state of an object to be observed.

[0002]

2. Description of the Related Art Conventionally, it has been desired in various fields to measure a voltage with high spatial resolution. Further, the probe is required to be non-destructive and not to electrically disturb the voltage distribution. In particular, in a semiconductor integrated circuit, since wiring is provided in submicron, a resolution of submicron or more is required even when inspecting a signal waveform in the circuit.
Conventionally, non-contact methods for probing voltage distribution include:
Some voltage probes having a high spatial resolution use a tunnel current (FIG. 9) and an electrostatic force (FIG. 10). The tunnel current I is approximately represented by the following equation.

I∝VDexp (−φZ) (1) Here, V is a bias voltage, D is a state density, φ is a tunnel barrier, and Z is a distance between the observed object and the probe. That is, if the tunnel current I is known, the bias voltage can be known.

FIG. 9 illustrates this method, which is a technique disclosed in the literature (Appl. Phys lett., (1986), Vol. 48 (8), p514). 1 is an object to be observed such as an integrated circuit, 201
And 202 are electrodes, 3 is a voltage applying means, 4 is a probe, 5
Is a current measuring means, and 6 is a conducting wire. In the example shown here, a voltage drop occurs because the observed object 1 has electric resistance, and a voltage distribution appears on the surface of the observed object 1. In this method, an ac voltage that changes sinusoidally with the dc voltage is applied to the probe 4. Depending on the applied voltage, dc voltage and ac
A tunnel current having a voltage component is induced. Also, a
The c voltage component is used for controlling the distance between the probe 4 and the observed object 1, and the applied voltage is controlled so that the dc voltage component becomes zero.
The voltage between the probe 4 and the observed object 1 can be determined from the applied voltage at that time.

FIG. 10 shows a method of measuring a surface potential using an electrostatic force, which is disclosed in "Technical Research Report of the Institute of Electronics, Information and Communication Engineers, OME92-3" published by the Institute of Electronics, Information and Communication Engineers.
Reference numeral 41 denotes a cantilever probe having a projection at the tip, and a conductor 411 is applied to the surface on the inspection side. The probe 41
The lower part of the tip forms a sharp part 412, and the tip of the sharp part 412 faces the surface of the observed object 1. The rear end portion of the probe 41 controls the movement of the probe 41 in the three axial directions of the plane XY and the vertical Z direction. As a result, the sharp portion 412 controls the relative positional relationship with the surface of the object 1 to be observed. Is done. 3 and 31 are voltage applying means,
Reference numerals 6, 61 and 62 denote conductors. The voltage applying means 3 is a conductor 6
A predetermined voltage is applied to the electrode 201 and the electrode 202 of the observed object 1 via the. Further, the voltage applying means 31 applies a predetermined voltage between the conductor 411 and the conductor 6.

The movement of the probe 41, that is, the distance between the surface of the object 1 to be observed and the probe 41 is a so-called "optical lever method".
The detection is controlled by a method referred to as The optical lever method is described in Appl. Phys. Lett., (1988), vol. 53 (12), p1045. In this optical lever method, a laser beam 30 emitted from a laser light source 28 is applied to the probe 41, and the reflected light is detected by a detector 29. The detector 29 has a two-part photodiode structure. According to this method, the distance in the vertical direction from the surface of the object to be observed can be detected on the order of nm, and this displacement is detected to measure the force acting on the probe 41.

[0007] When a voltage is applied to the probe 41 by the voltage applying means 31, an electrostatic charge is generated at the sharp portion 412 at the tip of the probe, and acts between the electrostatic charge generated on the surface of the object 1 to be observed. The potential distribution on the surface is obtained by detecting the electrostatic force. Further, in order to discriminate the electrostatic force acting on the probe 41 from other forces such as an atomic force, the voltage applied by the voltage applying means 3 is sinusoidally modulated, and the fundamental frequency of the response of the probe 41 to the voltage is modulated. The component or the double frequency is detected to obtain the surface potential.

[0008]

However, the above-mentioned conventional voltage probe has the following problems. Although the method shown in FIG. 9 can achieve high spatial resolution, it cannot be applied when the surface of the object to be observed is covered with an insulating material because a tunnel current is used.
As is apparent from the equation (1), the tunnel current differs depending not only on the bias voltage but also on the type of the object to be observed, and differs depending on the type of the material on the surface. Further, the same substance differs depending on the surface state. Therefore, quantitative measurement could be performed only under limited conditions. Eventually, the method shown in FIG. 9 has a problem in that the object to be observed is limited and versatility is poor.

From equation (1), the tunnel current is proportional to the voltage. Therefore, if you want to change the sensitivity,
Needs to be changed, but there is a problem that the resolution changes.

The method shown in FIG. 10 also has the advantage that a high spatial resolution can be obtained and the sensitivity does not depend on the size of the probe, but the probe is used to discriminate the electrostatic force from the force acting on the probe. It is necessary to vibrate forcibly. Due to this process, this method has a problem that the response speed is limited to the frequency of the forced vibration, and it is difficult to obtain a response speed on the order of MHz.

An object of the present invention is to provide a voltage distribution observing apparatus which is versatile and has a high spatial resolution.

Another object of the present invention is to provide a voltage probe capable of high spatial resolution and a method of manufacturing the same.

The above and other objects and novel features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

[0014]

The following is a brief description of an outline of typical inventions disclosed in the present application. That is, the semiconductor device supported by the voltage applying means for applying a predetermined voltage to the object to be observed according to the present invention, and an operating mechanism which allows the front end to face above the object to be observed and the rear end of which can be controlled in three axial directions. A voltage probe formed with a distance measuring mechanism that irradiates a laser beam to the voltage probe and detects reflected light with a detector to measure the distance between the observed object and the voltage probe.
The voltage probe is partially provided with a pn junction and provided with current detection means for detecting a current flowing between the junctions, and one electrode portion of the pn junction is electrically connected to a part of the object to be observed. It has a connected structure.
The voltage probe has a cantilever shape and has a pn junction as a voltage measuring means (voltage strength measuring means). In this voltage probe, the distance between the object to be observed and the voltage probe is controlled by an optical lever method.

In a voltage probe according to another embodiment of the present invention, a measuring tip of the voltage probe is a projection, and a periphery of the tip of the projection is covered with a metal film and a voltage exposed from the metal film. The probe portion becomes an opening, and the metal film is configured to be used after being adjusted to substantially the same voltage as the object to be observed.

In a method of manufacturing a voltage probe of a voltage distribution observation apparatus according to the present invention, a step of doping a first conductivity type determining impurity on a main surface of a semiconductor substrate to form a first conductivity type layer; Forming an epitaxial layer of the first conductivity type by epitaxial growth on the mold layer; and diffusing a second conductivity type determining impurity into a surface portion of the epitaxial layer to form a second conductivity type region to form a pn junction. Forming an electrode on each of the second conductivity type region and the epitaxial layer; and selectively forming an insulating film on the back surface of the semiconductor substrate. Etching the first conductivity type layer to form a cantilever-shaped voltage probe.

[0017]

According to the above-mentioned means, the voltage probe of the present invention has a structure having a pn junction as a voltage intensity measuring means, but the photocurrent generated at the pn junction depends on the voltage applied to the pn junction. . Therefore, when a minute voltage probe having a pn junction is brought close to the object to be observed, the voltage applied to the pn junction changes due to the voltage from the object to be observed, and the photocurrent changes. That is, a voltage distribution can be obtained by observing a change in photocurrent.

Since the voltage probe of the present invention is sensitive to only voltage in principle, it is excellent in versatility with respect to an object to be observed and measurement conditions.

In the voltage probe of the present invention, the detection of the photocurrent is based on the photocurrent generated at the pn junction.
The high frequency response is on the order of GHz, and the high frequency response is good.

Further, in the voltage probe of the present invention,
When a reverse bias is applied so that the operating point is in a region where an avalanche occurs, the voltage sensitivity is improved. This means that the sensitivity can be adjusted by adjusting the bias voltage.

The voltage probe of the present invention has a cantilever shape. As a result, since the optical lever method can be adopted, the distance between the photodetector and the object to be observed can be controlled on the order of nm, and the atomic force can also be used.

A voltage probe according to another embodiment of the present invention has a structure having an opening as a structure surrounded by a metal film at the tip of the voltage probe. And the spatial resolution increases.

In the method of manufacturing the voltage probe of the present invention, since the pn junction is formed by using the epitaxial layer formed on the main surface side of the semiconductor substrate, the pn junction is formed by the voltage from the object to be observed. Using the change in the voltage applied to the junction, the change in the photocurrent can be observed with high accuracy, and the voltage distribution on the surface of the object to be observed can be detected with high accuracy.

Further, since the voltage probe of the present invention uses the epitaxial layer provided on the semiconductor substrate side as the main body of the voltage probe, a fine and highly accurate voltage probe can be formed.

[0025]

An embodiment of the present invention will be described below with reference to the drawings. In all the drawings for describing the embodiments, components having the same function are denoted by the same reference numerals, and their repeated description will be omitted.

FIG. 1 is a schematic diagram showing an outline of a voltage distribution observation apparatus using a voltage probe according to one embodiment of the present invention. In the present embodiment, the voltage distribution observation apparatus having the structure shown in FIG. 10 is different from the voltage probe only in the voltage probe and the one attached to the voltage probe. Electrodes 201 and 202 are provided on the upper surfaces of both ends of the object 1 to be observed such as an integrated circuit, respectively.
A predetermined voltage is applied to the electrode 1 and the electrode 202 by the voltage applying means 3 via the conducting wire 6.

A scanning mechanism 52 is provided above the object 1 to be observed, and a voltage probe 42 is inclined from the scanning mechanism 52 and extends in a cantilever shape.
The tip of the voltage probe 42 faces near the surface of the observed object 1.

In order to measure the distance between the surface of the object 1 to be observed and the voltage probe 42, an optical lever method is employed. That is, on the upper surface side of the voltage probe 42, a laser beam 30 emitted from the laser light source 28 is applied to the voltage probe 42, and the reflected light is detected by the detector 29. In this embodiment, a visible light laser is used. The detector 29
Has a two-segmented photodiode structure. According to this method, it is possible to detect the vertical distance between the observed object 1 and the voltage probe 42 on the order of nm. Further, by detecting this displacement, the force acting on the voltage probe 42 is detected.

The voltage probe 42 is formed of a semiconductor. Here, production (manufacture) of the voltage probe 42
The method will be described with reference to FIGS. As shown in FIG. 2, first, a silicon (semiconductor) substrate 33 having a thickness of several 100 μm is prepared. This silicon substrate 3
In No. 3, the plane orientation of the main surface is (100). On the main surface of the silicon substrate 33, a p-type semiconductor layer 32 doped with boron (acceptor) having a thickness of several μm is formed. The semiconductor layer 32 has a thickness of several μm.
A p-type layer 23 of an epitaxial layer is formed.
On the back (lower) surface of the silicon substrate 33, a silicon oxide film 34 having a thickness of several μm is formed by a sputtering method.
Is provided.

Next, as shown in FIG. 3, an n region 24 doped with phosphorus serving as a donor is formed at one end of the p-type layer 23 by ordinary photolithography.
3 and a pn junction is formed. The position of the pn junction was adjusted under annealing conditions after doping. Since the absorption coefficient α of silicon in the visible region is approximately 5 μm −1, the position of the pn junction is preferably several μm or less from the side exposed to the laser beam 30 from the laser light source 28.

Next, the p-type layer 23 and the n region 24
An insulating film 25 is selectively formed on the upper surface of
A p + -type high impurity concentration region 231 and an n + -type high impurity concentration region 241 are partially formed as ohmic contact regions in the surface layers of the p-type layer 23 and the n region 24. The p + -type high impurity concentration region 231 and the n + -type high impurity concentration region 241 have higher concentrations than the p-type layer 23 and the n region 24, respectively. (For example, phosphorus) was heavily doped.

Next, electrodes 21 and 22 made of aluminum are formed on the exposed p + -type high impurity concentration regions 231 and n + -type high impurity concentration regions 241, respectively.

Next, as shown in FIG. 4, the right end portion where the p-type layer 23 and the n region 24 overlap with each other is removed by etching into a desired shape (a predetermined length a in the figure).
A polyimide layer 35 is formed by coating the main surface of the silicon substrate 33, that is, the surface on which the electrodes 21 and 22 are provided, with polyimide.

Next, as shown in FIG. 4, the silicon oxide film 34 on the back surface of the silicon substrate 33 is etched away except for the lengths b and c at both ends. The remaining portion c of the silicon oxide film 34 is shorter than the etching length a (a> c).

Next, as shown in FIG. 5, the silicon substrate 33 is anisotropically etched using the silicon oxide film 34 as a mask, and the semiconductor layer 32 is etched away using the remaining silicon substrate 33 as a mask. Also,
The polyimide layer 35 and the silicon oxide film 34 are also removed by etching. As a result, as shown in FIG. 6, only one (rear end) is as thick as several 100 μm and the other part is several μm.
Is formed.

The polyimide layer 35 is for protecting the upper structure when the silicon substrate 33 is etched. The silicon oxide film 34 was etched by standard dry etching. The silicon substrate 33 was etched using an alkaline etchant, for example, an aqueous solution of ethylenediamine pyrocatechol. According to this etchant, the semiconductor layer 32 doped with boron becomes an etch stop layer. In addition, a part of the silicon substrate 33 that is anisotropically etched depending on the plane orientation of the crystal and is not etched remains, and functions as a mask when the semiconductor layer 32 is etched later.

As a result, a voltage probe 42 as shown in FIG. 6 is formed. The rear end side of the voltage probe 42 having the remaining silicon substrate 33 is a fixed side having a cantilever shape, and is attached to the operation mechanism 52. In addition, at the time of this attachment, it is attached so that the surface side having the electrodes 21 and 22 faces the object 1 to be observed.

According to such a method of manufacturing the voltage probe 42, a fine and highly accurate voltage probe can be manufactured.

On the other hand, as shown in FIG. 1, the electrode 21 and the electrode 22 are connected to a current detecting means 20 through a conducting wire 27.
Are connected to detect a photocurrent. The conducting wire 27 on the side connected to the electrode 22 and the electrode 202 of the object under observation 1 are connected by a conducting wire 271 and have substantially the same potential (earth).

In such a voltage distribution observation device,
A bias voltage is applied to the p-type layer 23 by the voltage on the surface of the object 1 to be observed. When the voltage probe 42 is scanned by the scanning means 52, the voltage p varies according to the voltage distribution of the observed object 1.
The bias voltage between the mold layer 23 and the n region 24 changes, and a photocurrent corresponding to the bias voltage can be detected by the current detection unit 20.

On the other hand, if a dc voltage applying means is newly added to the voltage applying means 3 and the operating point is set to a bias voltage slightly smaller than a bias condition under which the pn junction causes an avalanche, the voltage sensitivity is improved. That is, this sensitivity can be adjusted by the dc bias voltage. The spatial resolution is approximately the size of the pn junction as described above.
It is effective to improve the resolution by reducing the size of the pn junction and implanting ions with an ion beam to modulate the composition and reduce the effective area of the pn junction.

The detector 29 is a means for detecting the position of a laser spot, and is, for example, a two-division photodiode. With this configuration, the vertical distance between the surface of the object to be observed of the voltage probe 42 and the surface of the object to be observed of the voltage probe 42 can be detected on the order of nm by the optical lever method described above. Since the voltage sensed by the voltage probe 42 decreases as the distance from the surface of the observed object 1 increases, the voltage probe 42
It is necessary to measure the distribution while maintaining a certain distance near the surface of the object 1 to be observed.

Also, in this embodiment, p-type light
Voltage probe 42 made of a semiconductor having an n-junction inside
Is irradiated with a laser beam 30. FIG. 7 shows the relationship between the photocurrent and the applied reverse bias voltage when light of a constant intensity is applied to the pn junction. That is, the applied voltage can be obtained by measuring the magnitude of the photocurrent.

As the scanning mechanism 52, a mechanism that can be driven in the x, y, and z-axis directions by combining piezo elements is used. A driving mechanism using a piezo element can perform position control with an accuracy of nm or less, so that the accuracy of voltage measurement can be improved. Voltage probe 4 by optical lever method
2 enables precise distance control. In addition, similar to a normal atomic force microscope, an object 1 to be observed can be controlled by a control signal.
Can be obtained at the same time.

According to such a voltage distribution observation device and voltage probe, the following effects can be obtained.

(1) The voltage probe of the present invention has a structure having a pn junction as a voltage intensity measuring means.
The photocurrent generated at the pn junction depends on the voltage applied to the pn junction. Therefore, when a minute voltage probe having a pn junction is brought close to the object to be observed, the voltage applied to the pn junction changes due to the voltage from the object to be observed, and the photocurrent changes. That is, an effect is obtained in that a voltage distribution can be obtained by observing a change in photocurrent.

(2) Since the voltage probe of the present invention is sensitive only to voltage in principle, it has an effect of being excellent in versatility with respect to an object to be observed and measurement conditions.

(3) In the voltage probe of the present invention, the detection of the photocurrent is based on the photocurrent generated at the pn junction.
The high-frequency response is on the order of GHz, and the effect of improving the high-frequency response is obtained.

(4) In the voltage probe of the present invention,
When a reverse bias is applied so that the operating point is in a region where an avalanche occurs, an effect of improving voltage sensitivity can be obtained. This means that the sensitivity can be adjusted by adjusting the bias voltage.

(5) The voltage probe of the present invention has a cantilever shape. As a result, since the optical lever method can be employed, the distance between the photodetector and the object to be observed can be controlled on the order of nm, and the effect that the interatomic force can be used can be obtained.

(6) In the method of manufacturing the voltage probe of the present invention, since the pn junction is formed by using the epitaxial layer formed on the main surface side of the semiconductor substrate, the voltage probe is Using the change in the voltage applied to the pn junction by the voltage, the change in the photocurrent can be observed with high accuracy, and the voltage distribution on the surface of the object to be observed can be detected with high accuracy.

(7) Since the voltage probe of the present invention uses the epitaxial layer provided on the semiconductor substrate side as the main body of the voltage probe, an effect that a fine and highly accurate voltage probe can be formed can be obtained.

As described above, the present invention has been specifically described based on the embodiments. However, it is needless to say that the present invention is not limited to the above-described embodiments, and can be variously modified without departing from the gist thereof. For example, instead of the pn junction, p
The same effect as in the above embodiment can be obtained by using a pin junction in which an i-layer (insulating layer) is provided between the mold layer and the n-type layer.

FIG. 8 is a schematic diagram showing a voltage probe 42 according to another embodiment of the present invention. The voltage probe 42 of this embodiment has a structure having a triangular pyramid-shaped projection 50 whose tip is sharpened downward. The periphery of the projection 50 is covered with a metal film 51, and only the tip of the projection 50 is exposed from the metal film 51.
The portion protruding from the metal film 51 becomes an opening 55 for detection.

Since the spatial resolution is about the size of the pn junction, reducing the size as much as possible leads to an improvement in resolution. Therefore, as shown in FIG.
When the n-junction is coated with a metal film (conductive film) 51,
The coated portion of the projection becomes equipotential, and the voltage is sensed by the so-called “electrostatic shielding” effect which is connected to a part (ground in the figure) of the sample (object to be observed).
There will be only 5 parts. That is, the size of the opening 55 becomes the size of the effective pn junction (detection unit), and the resolution can be improved.

In this embodiment, since the resolution is determined by the tip diameter of the voltage probe 42, a high spatial resolution can be achieved. Further, the needle shape of the voltage probe can be observed even when the object to be observed 1 is a sample having large unevenness such as a groove, and it goes without saying that the voltage probe is advantageous in terms of versatility. In this example, the protrusion 50 is a document (Appl. Phys.
tt. (1990), vol.57 (3), p316)
Triangular pyramidal projections were formed. This method is based on the fact that silicon dissolves in an alkaline solution, for example, an aqueous solution of potassium hydroxide or an aqueous solution of ethylenediamine pyrocatechol depending on the plane orientation.

According to this method, the radius of curvature at the tip is 1
Triangular pyramid-shaped silicon needles of 00 nm or less could be formed stably.

Since the height of the projection is several μm or less and visible light is transmitted through silicon for about several μm (absorption coefficient α in the visible region of silicon is approximately 5 μm −1), light scattered inside the projection is also a pn junction. Part can be reached.

Various other methods have been proposed as a method for forming the needle-shaped protrusions. Needless to say, the protrusions can be formed by a method other than the above-described method. For example, J. Vac. Sci. (1990), vol. A8 (4), p3386 discloses various projection production methods.

[0060]

The effects obtained by typical ones of the inventions disclosed in the present application will be briefly described as follows. Since the voltage distribution observation device of the present invention does not use a tunnel current, the voltage distribution observation is possible even if the surface of the object to be observed is covered with an insulating material,
It will be versatile.

The voltage probe of the present invention has a structure having a pn junction as a voltage intensity measuring means.
The photocurrent generated at the pn junction depends on the voltage applied to the pn junction. Therefore, when a minute voltage probe having a pn junction is brought close to the object to be observed, the voltage applied to the pn junction changes due to the voltage from the object to be observed, and the photocurrent changes. That is, an effect is obtained in that a voltage distribution can be obtained by observing a change in photocurrent.

Further, since the voltage probe of the present invention is sensitive only to voltage in principle, it has an effect of being excellent in versatility with respect to an object to be observed and measurement conditions.

In the voltage probe of the present invention, the detection of the photocurrent is based on the photocurrent generated at the pn junction.
The high-frequency response is on the order of GHz, and the effect of improving the high-frequency response is obtained.

In the voltage probe of the present invention,
When a reverse bias is applied so that the operating point is in a region where an avalanche occurs, an effect of improving voltage sensitivity can be obtained. This means that the sensitivity can be adjusted by adjusting the bias voltage.

The voltage probe of the present invention has a cantilever shape. As a result, since the optical lever method can be employed, the distance between the photodetector and the object to be observed can be controlled on the order of nm, and the effect that the interatomic force can be used can be obtained.

In the method of manufacturing the voltage probe of the present invention, since the pn junction is formed using the epitaxial layer formed on the main surface side of the semiconductor substrate, the voltage from the object to be observed is By using the change in the voltage applied to the pn junction, the change in the photocurrent can be observed with high accuracy, and the voltage distribution on the surface of the object to be observed can be detected with high accuracy.

Further, since the voltage probe of the present invention uses the epitaxial layer provided on the semiconductor substrate side as the main body of the voltage probe, there is obtained an effect that a fine and highly accurate voltage probe can be formed.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an outline of a voltage distribution observation device according to an embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view showing a semiconductor substrate or the like serving as a voltage probe material in a method of manufacturing a voltage probe in the voltage distribution observation device according to one embodiment of the present invention.

FIG. 3 illustrates a method of manufacturing a voltage probe according to the present embodiment.
FIG. 3 is a schematic cross-sectional view showing a semiconductor substrate and the like on which an n-junction is formed.

FIG. 4 is a schematic cross-sectional view showing a semiconductor substrate or the like in which a polyimide film is formed on the main surface side of the semiconductor substrate in the method of manufacturing the voltage probe of the present embodiment.

FIG. 5 is a schematic cross-sectional view showing a semiconductor substrate and the like in a state where an unnecessary semiconductor substrate portion is removed in the method of manufacturing the voltage probe of the present embodiment.

FIG. 6 is a schematic cross-sectional view showing a voltage probe formed by removing unnecessary portions in the method of manufacturing the voltage probe according to the present embodiment.

FIG. 7 is a graph showing a correlation between a photocurrent and an applied voltage when light of a constant intensity is applied to a pn junction of the voltage probe of the present embodiment.

FIG. 8 is a schematic sectional view showing a voltage probe according to another embodiment of the present invention.

FIG. 9 is a schematic diagram showing an outline of a conventional voltage distribution observation device using a voltage probe.

FIG. 10 is a schematic diagram showing an outline of a conventional voltage distribution observation device using another voltage probe.

[Explanation of Symbols] 1 ... Observed object, 3 ... Voltage applying means, 4 ... Probe, 5 ... Current measuring means, 6 ... Conducting wire, 20 ... Current detecting means, 21 and 22
2 ... electrode, 27 ... conductive wire, 28 ... laser light source, 29 ... detector, 30 ... laser beam, 31 ... voltage applying means, 33
... silicon substrate, 41 ... probe, 42 ... voltage probe, 5
0: Projection, 52: Scanning mechanism, 55: Opening, 61: Conducting wire, 201, 202: Electrode, 231: P + type high impurity concentration region, 241: n + type high impurity concentration region, 271: Conducting wire, 411 ... Conductor, 412: Sharp part.

Claims (6)

(57) [Claims] 1. A semiconductor device which is supported by a voltage applying means for applying a predetermined voltage to an object to be observed, and an operation mechanism having a front end facing the object to be observed and a rear end capable of being controlled in three axial directions. A voltage probe formed of a, a distance measuring mechanism for irradiating the voltage probe with a laser beam and detecting reflected light with a detector to measure the distance between the object to be observed and the voltage probe, and the voltage probe The probe is partially provided with a pn junction or a pin junction, and provided with current detection means for detecting a current flowing between the junctions, and one electrode portion of the pn junction or the pin junction is a part of the object to be observed. A voltage distribution observing device electrically connected to the terminal. 2. A voltage probe for a voltage distribution observing device having a front end facing an object to be observed to which a predetermined voltage is applied and a rear end supported by an operation mechanism capable of controlling three axes. The voltage probe has a pn junction or pin
A voltage probe comprising a junction. 3. The voltage probe according to claim 2, wherein the voltage probe has a cantilever shape. 4. The voltage probe according to claim 2, wherein:
The measurement tip of the voltage probe becomes a projection, and the periphery of the tip of the projection is covered with a metal film, and the voltage probe portion exposed from the metal film forms an opening, and the metal film is further covered. A voltage probe, which is used by being adjusted to substantially the same voltage as that of an observation object. 5. A pn junction or pin junction or pi
A part of the n-junction is left, and the remaining part is
3. The voltage probe according to claim 2, wherein the voltage probe has a different chemical composition or a different crystal structure from the junction, the pin junction, or the pin junction. 6. A method of manufacturing a voltage probe for a voltage distribution observation device, comprising: doping a first conductivity type determining impurity on a main surface of a semiconductor substrate to form a first conductivity type layer; Forming an epitaxial layer of the first conductivity type on the conductivity type layer by epitaxial growth, and forming a second conductivity type region by diffusing a second conductivity type determining impurity in a surface portion of the epitaxial layer to form a pn junction Forming an electrode on each of the second conductivity type region and the epitaxial layer; and selectively forming an insulating film on the back surface of the semiconductor substrate, and then using the insulating film as an etching mask to form the semiconductor substrate. Forming a cantilever-shaped voltage probe by removing the first conductivity type layer by etching.