JPH11214706A - Semiconductor sensor and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a structure and manufacturing method of semiconductor sensor having stopper structure, while capable of being manufactured with fewer number of processes. SOLUTION: Comb-tooth structures 13, 14 are respectively provided on weight parts and fixing parts to specify a gradient offset angle θ, so that the opposite surfaces of the comb-tooth structures 13, 14 correspond to the gradient surfaces 13a, 13b, 14a, 14b making the comb tooth structures 13, 14 overlap with one another. In such a constitution, even if the weight parts caught by acceleration are displaced, the displacement size is limited within a range of the comb-tooth structures 13, in contact with the comb-tooth structures 14. Moreover, the left half and right half gradients are inverted so as to offset the lateral directional stresses at contacting. Furthermore, this structure can be formed in ewer number of processes by ion etching step, by sobiecting ions to impression of electric field in the lateral direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor sensor for detecting an input mechanical quantity by a minute deformation of a semiconductor structure. More specifically, the present invention relates to a semiconductor sensor and a method for manufacturing the semiconductor sensor, which can form a stopper structure for preventing excessive deformation when an excessive mechanical quantity is input by a simple manufacturing process.

[0002]

2. Description of the Related Art Conventionally, there has been proposed a semiconductor sensor for detecting a physical quantity such as acceleration by a semiconductor device. In this semiconductor sensor, a structure having a fixed portion and a weight portion is formed in a semiconductor, and the semiconductor device is deformed by inputting a mechanical quantity so that a minute displacement occurs between the fixed portion and the weight portion.
Due to this displacement, the beam part connecting the weight part to the fixed part is distorted, and the positional relationship between the fixed part and the weight part changes, so the mechanical quantity is detected by detecting these electrically. It is. In order to detect the distortion, a piezoresistive element is formed on the beam portion, and the change in the electric resistance due to the distortion may be observed. In order to detect a change in the positional relationship between the fixed portion and the weight portion, electrodes may be provided on the fixed portion and the weight portion, and the change in the capacitance between the two electrodes may be observed.

In this type of semiconductor sensor, when an excessive mechanical quantity is input, the displacement between the fixed portion and the weight portion may be excessive. Due to this excessive displacement, the beam may be broken, or a so-called misstep may occur in which the beam does not return to its original position even if the displacement is recovered without breaking, and the sensor may not be used. Such a situation occurs when the sensor is dropped due to careless handling or the like. Therefore, it is necessary to prevent the weight portion from being excessively displaced with respect to the fixed portion.

As a conventional example of a semiconductor sensor for preventing such an excessive displacement, there is one disclosed in Japanese Patent Publication No. 7-40045. As shown in FIG. 15, the semiconductor acceleration sensor of the publication has an annular fixing portion 101 and a weight portion 102 provided therein, and the fixing portion 101 is provided with a first protrusion 104. The weight portion 102 is provided with a second protrusion 105. The fixed portion 101 and the weight portion 102 are connected by a beam portion 103. When acceleration is applied to this structure in the vertical direction (arrows α ₁ , α ₂ ) in the figure, the weight portion 102 is vertically displaced with respect to the fixed portion 101 due to inertia, so that acceleration can be detected. However, when the displacement increases, the first protrusion 104 and the second protrusion 105 come into contact with each other, and further displacement is hindered. Further, by reversing the positional relationship between the first projection 104 and the second projection 105 depending on the location, it is possible to respond to an impact in any direction, up and down.

The semiconductor sensor shown in FIG. 15 is manufactured as follows. First, as shown in FIG. 16, n-type silicon layers 107, 108, and 109 are sequentially stacked on a p-type silicon semiconductor substrate 100 by an epitaxial growth method, and a p-type silicon window is formed on each silicon layer by a thermal diffusion method. 1
10, 111 and 112 are formed each time the layers are stacked. And
When a p-type silicon is selectively etched by an electrochemical etching method (Japanese Patent Application Laid-Open No. 61-97572, etc.) with a mask of an appropriate shape, a part of the semiconductor substrate 100 and the p-type silicon are etched as shown in FIG. Window 110,
111 and 112 are etched. As a result, a part of the semiconductor substrate 100 and a part of n-type silicon remain, and only the wafer process is performed without using a process such as bonding.
Is obtained. The windows 110, 111, 112
May be silicon oxide obtained by partially thermally oxidizing the silicon layers 107, 108, and 109, and in that case, the etching method is made suitable.

[0006]

However, the conventional semiconductor sensor described above has the following problems. That is, in the manufacturing process, it is necessary to repeat the epitaxial growth and the partial thermal diffusion (or thermal oxidation) many times before etching, so that although it can be manufactured only by the wafer process, it is considerably complicated. For this reason, the manufacturing cost is considerably high, which is a hindrance to the widespread use of semiconductor sensors. Further, the fact that the number of times of partial thermal diffusion (or thermal oxidation) is large means that the number of times of photolithography is also large, and it can be said that problems due to photomask alignment accuracy tend to occur.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the conventional semiconductor sensor and its manufacturing method. That is, an object of the present invention is to provide a structure and a manufacturing method of a semiconductor sensor which can be manufactured with a small number of processes, to eliminate manufacturing difficulties, and to make the semiconductor sensor usable for a wide range of applications.

[0008]

SUMMARY OF THE INVENTION A semiconductor sensor according to the present invention having an object to solve this problem has a fixed portion and a weight portion, and detects a dynamic quantity by displacement of the weight portion with respect to the fixed portion. Wherein a first surface inclined at a predetermined offset angle with respect to the direction of displacement is formed on the fixed portion, and a second surface opposed to the first surface is formed on the weight portion. The second surface is formed at a position where the weight portion can be brought into contact with the first surface by being displaced in the direction of the displacement.

In this semiconductor sensor, when a dynamic quantity is applied, the weight is displaced with respect to the fixed part. Therefore, by detecting this displacement, the applied dynamic quantity can be detected. That is, when acceleration (a kind of mechanical quantity) is applied to the fixed portion, the movement of the weight portion is delayed due to inertia, and displacement with respect to the fixed portion occurs. This displacement causes a change in the capacitance between the electrodes provided on the fixed portion and the weight portion, respectively. Therefore, by detecting the change in the capacitance, the magnitude of the applied acceleration can be detected. Or, if the weight vibrates relative to the fixed part, the angular velocity (also a kind of mechanical quantity)
Is applied, the weight portion is displaced with respect to the fixed portion due to Coriolis force. In this case, the magnitude of the applied angular velocity can be detected by detecting a change in the capacitance. However, means for driving the weight portion to vibrate with respect to the fixed portion is required. In these cases, when the weight portion is displaced, the portion connecting the weight portion and the fixed portion is distorted. Therefore, instead of detecting a change in capacitance, the distortion may be detected by a piezo element or the like.

Here, when the displacement of the weight portion with respect to the fixed portion increases and the second surface comes into contact with the first surface,
Further displacement is hindered. For this reason, even if an excessive mechanical amount is applied due to an impact or the like, the displacement of the weight portion does not become excessive. That is, the first surface and the second surface form a stopper structure, thereby preventing the semiconductor sensor from being broken or misstepped.

In this semiconductor sensor, two sets of the first surface and the second surface are provided, and the offset angle of each set is opposite to the direction of the displacement. desirable. This is because the lateral stress generated by the inclination (offset angle with respect to the direction of displacement) of the first surface when the second surface contacts the first surface is thereby canceled. Here, the "set" of the first surface and the second surface does not necessarily indicate one pair of both surfaces. Each "set" may include a number of first and second surfaces, respectively.

The first surface and the second surface of the semiconductor sensor are formed by performing inclined anisotropic etching on the semiconductor layer (gradient etching step). That is, when anisotropic etching is performed on the semiconductor layer from a direction inclined at a predetermined offset angle, surfaces inclined at a predetermined offset angle are formed on both sides of the portion removed by the etching. Of course, they are opposed to each other, and these may be used as the first surface and the second surface. By forming the fixed part and the weight part by a known method such as film formation, photolithography or etching together with, before or after the formation of the first surface and the second surface, the semiconductor sensor according to the present invention is provided. Is manufactured.

Here, the inclined etching step for forming the first surface and the second surface can be performed by performing reactive ion etching while applying a horizontal electric field. In normal reactive ion etching, a vertical electric field is applied to the reactive ions to etch the semiconductor layer vertically, but by further applying a horizontal electric field, the reactive ions are accelerated in an oblique direction. Therefore, the semiconductor layer is attacked, so that the anisotropic etching proceeds in the inclined direction. At this time, the electric field strength in the lateral direction may be determined so that the traveling direction of the reactive ions reaching the semiconductor layer is inclined at a predetermined offset angle with respect to the normal direction of the semiconductor layer.

[0014]

Embodiments of the present invention will be described below in detail with reference to the drawings. The present embodiment is a semiconductor acceleration sensor that detects acceleration based on a change in capacitance between a substrate and a weight portion.

[Structure] The semiconductor sensor 1 according to the present embodiment basically has a lattice-shaped weight portion 11 and a support portion 12 arranged on a semiconductor substrate 10 as shown in the plan view of FIG. , And comb-shaped structures 13 and 14 are formed between them. Here, the support portion 12 is fixed on the semiconductor substrate 10 via the oxide layer 50 as shown in the AA cross-sectional view of FIG. On the other hand, the weight portion 11 is in a state of floating with respect to the semiconductor substrate 10 as shown in the BB sectional view of FIG. The size of the weight portion 11 is about several hundred μm square. In order to hold the weight portion 11, anchor portions 16 are provided at four places on the semiconductor substrate 10. The anchor portion 16 is fixed on the semiconductor substrate 10 via the oxide layer 50 as in the fixing portion 12, as shown in a cross-sectional view taken along line DD of FIG. The weight 11 is composed of four beams 17.
Are connected to and held by four anchor portions 16. The beam portion 17 is in a state of being floating with respect to the semiconductor substrate 10 as in the case of the weight portion 11, as shown in the EE cross-sectional view of FIG.

Weight portion 11, support portion 12, comb structure 1
3, 14, the anchor portion 16, and the beam portion 17 are all crystalline silicon. These are all electrically insulated from the semiconductor substrate 10. Further, the weight portion 11, the comb structure 13, the anchor portion 16, the beam portion 17, and the support portion 12
The comb structure 14 is also electrically insulated.
In this structure, the weight portion 11 held in a floating state with respect to the semiconductor substrate 10 can be displaced vertically in FIG. When the weight 11 is displaced, the four beams 17 are distorted. In FIG. 1, the support portion 12 and the anchor portion 16 have a certain area, but other than the weight portion 11, the comb-shaped structures 13, 1
4. The beam portion 17 is formed in a narrow linear shape.

A comb-shaped structure 13 is provided on a side surface of the weight portion 11 facing the support portion 12. On the other hand, a comb-shaped structure 14 is provided on a side surface of the support portion 12 facing the weight portion 11. The comb structure 13 and the comb structure 14 are arranged alternately. These are floating with respect to the semiconductor substrate 10 and are formed to be inclined, as shown in the CC sectional view of FIG. The direction of the inclination is reversed between the left half (L region) and the right half (R region) in FIGS. 1 and 6 with respect to the normal direction.

The comb structures 13, 14 will be further described with reference to an enlarged sectional view of FIG. As shown in FIG. 7, since the inclined comb-tooth structures 13 and the comb-tooth structures 14 are alternately arranged, the upper inclined surface 13 a of the comb-tooth structure 13 and the lower portion of the comb-tooth structure 14. Side inclined surface 14a. Similarly, the lower inclined surface 13b of the comb structure 13 and the upper inclined surface 14b of the comb structure 14 face each other. Each inclined surface 13a, 13b, 14a, 14b is parallel to each other.

The vertical dimension h of each of the comb-tooth structures 13 and 14, the horizontal distance k between each of the comb-tooth structures 13 and 14, and the offset of each of the inclined surfaces 13a, 13b, 14a and 14b. The angle θ has a relationship represented by the following inequality. The offset angle θ is an angle between the inclined surface and the normal v. k <htan θ (1) That is, the comb-tooth structures 13 and 14 overlap each other, and the semiconductor substrate 10 below does not look into the gap between them even when viewed from directly above. FIG. 7 is an enlarged view of the L region in FIG. 6, and the R region has a symmetrical shape.

[Operation] The semiconductor sensor 1 having the above structure operates as follows. That is, in the semiconductor sensor 1, when receiving acceleration in the up-down direction, the weight portion 11 moves later than the substrate 10, which is a fixed portion, due to its inertia. For this reason, the weight portion 11 is displaced in the vertical direction with respect to the substrate 10. By providing appropriate electrodes on the weight portion and the fixed portion and detecting the capacitance therebetween, the degree of such displacement can be reduced. That is, the magnitude of the acceleration received by the semiconductor sensor 1 can be known.

When the acceleration input to the semiconductor sensor 1 is large, the displacement of the comb structure 13 with respect to the comb structure 14 also increases. However, in the semiconductor sensor 1, the comb structure 13
When an acceleration exceeding a certain level is applied by the above-described inclined structure of FIGS.
3 comes in contact with the comb structure 14 and further displacement is prevented. FIG. 8 shows a state in which the comb structure 13 is displaced upward and is in contact with the comb structure 14. However, even when the comb structure 13 is displaced downward, the comb structure 13 similarly contacts the comb structure 14. Displacement is hindered. That is, the comb structure 1
The inclined surfaces 13a, 13b, 14a, and 14b of 3, 14 are
Has a stopper structure. Therefore, even if the semiconductor sensor 1 is impacted due to carelessness such as being dropped on the floor and an excessive acceleration is input, the displacement of the comb-tooth structure 13 with respect to the comb-tooth structure 14 does not increase infinitely. For this reason, the beam portion 17 is not excessively distorted and does not break. Further, there is no so-called misstep in which the comb structure 13 and the comb structure 14 are shifted by one step when the displacement is recovered.

When the comb-tooth structure 13 contacts the comb-tooth structure 14 as shown in FIG. 8, lateral stress is generated by the inclined structure of the comb-tooth structures 13 and 14. Since the lateral stress acts as a compressive stress or a tension on the beam 17, if the stress is too large, the beam 17 may be broken and the semiconductor sensor may be broken. However, the semiconductor sensor 1 has the L region and the R region in which the inclination offset angles of the comb-tooth structures 13 and 14 are opposite as shown in FIGS. In the above, the transverse stress generated is in the opposite direction. Therefore, most of the stress in the lateral direction is actually canceled out, and does not act as a compressive stress or a tension on the beam portion 17. Therefore, the beam portion 17 does not break.

[Manufacturing] The semiconductor sensor 1 having the above-described structure and operation is manufactured as follows. First, a so-called SOI wafer 20 having an internal oxide layer as an original substrate is prepared. The SOI wafer 20 has a lower semiconductor layer 10, an internal oxide layer 50, and an upper semiconductor layer 51, as shown in FIG. Of these, the upper semiconductor layer 51 is processed, and the weight portion 11, the support portion 12, the comb-shaped structures 13, 1
4, an anchor portion 16 and a beam portion 17. Further, the internal oxide layer 50 is partially processed and remains, and serves as a portion for holding the support portion 12 and the anchor portion 16 on the lower semiconductor layer 10.

On the SOI wafer 20, the upper semiconductor layer 51 in the L region in FIG. 1 is first etched, and the weight portion 11, the support portion 12, the comb structures 13, 14, the anchor portion 16, the beam portion 17, Leave the part that becomes. This etching is performed by using reactive ion etching which is anisotropic etching, and is performed by obliquely incident ions. For this reason, as shown in FIG.
6 (hereinafter referred to as “RI
E device ”) 60 is used. This RIE device 60
Has side electrodes 65 and 66 in a chamber 61 in addition to normal electrodes 62 and 63 connected to a high-frequency power supply 64. The side electrodes 65 and 66 are connected to a DC power supply 67, and a lateral electric field can be applied between them.

Therefore, on the SOI wafer 20, only the L region is patterned and the R region is formed as a solid film as a resist mask, which is mounted on the electrode 63 of the RIE apparatus 60. At this time, the horizontal direction (A-
A direction) is the side electrodes 65, 6 in the RIE device 60.
6 is placed so as to coincide with the normal direction. Then, when etching is performed while applying a horizontal electric field from the DC power supply 67, the ions are obliquely incident on the upper semiconductor layer 51 under the influence of the horizontal electric field, so that the etching proceeds in an inclined direction. The inclination angle of the incident direction of the ions at this time determines the offset angle θ shown in FIG. Under normal processing conditions, this offset angle θ is 20 °.
If the degree is sufficient, the above-mentioned expression (1) is satisfied, and the comb tooth structure 1
3, 14 can overlap each other.
Therefore, it is necessary to set the electric field strength in the lateral direction so that the required offset angle can be obtained. This electric field strength depends on the voltage between the side electrodes 65 and 66,
This is adjusted according to 7.

FIG. 11 is a cross-sectional view taken along the line CC in a state where the etching is performed and the resist mask is removed. In this state, in the R region, the upper semiconductor layer 51 is left as it is, but in the L region, it is processed to form the comb-shaped structure 1.
3 and 14. The comb structures 13 and 14 are
It has the inclined structure described in FIG. At this point, the weight portion 11, the support portion 12, and the like are also in a state where only the L region is processed, and the entire oxide layer 50 remains as it is.

Next, the processed L region is flattened in preparation for the processing of the R region. Therefore, the oxide film 5 is formed by CVD.
2 is deposited (see FIG. 12), and the oxide film 52 on the surface is etched with hydrofluoric acid (see FIG. 13). In this state, the gap between the comb-shaped structures 13 and 14 in the L region is filled with the oxide film 52 and flattened.

Then, the R region is processed. That is, contrary to the above-described processing of the L region, only the R region is patterned, and the L region forms a solid film resist mask. Then, this is placed on the electrode 63 of the RIE device 60. The orientation of the wafer at the time of mounting is the same as in the processing of the L region. Then, etching is performed. At this time,
The polarity of the DC power supply 67 is reversed from that in processing the L region. As a result, a lateral electric field is applied between the side electrodes 65 and 66 in a direction opposite to that in the processing of the L region. For this reason, ions inclined in a direction opposite to that in the processing of the L region enter the upper semiconductor layer 51 of the R region, and the etching proceeds in a symmetric direction. Thus, the comb-tooth structures 13 and 14 which are symmetrically formed between the R region and the L region are formed. FIG. 14 shows a cross-sectional view taken along the line CC in this state. At this point, the weight portion 11 and the support portion 12 are also processed in both the L and R regions.

Then, this is etched with hydrofluoric acid.
Then, the oxide layer 52 and the oxide film 52 filling the gap between the comb-shaped structures 13 and 14 in the L region are removed. At this time, the portions under the comb structures 13 and 14 of the oxide layer 50 are also removed. This is because the etching with hydrofluoric acid proceeds isotropically, so that the lower portions of the narrow comb-tooth structures 13 and 14 are also etched. Thus, a state in which the comb-tooth structures 13 and 14 are separated from the lower semiconductor layer 10 as shown in FIG. 6 is obtained. At this time, the weight 11 and the beam 1
7, the oxide layer 50 is also removed.
The state shown in FIG. However, since the etching does not reach the lower portions of the support portion 12 and the anchor portion 16 having a certain area, the oxide layer 50 remains in these portions as shown in FIGS. The state fixed to 10 is maintained. Thus, the semiconductor sensor 1 is manufactured.

As described above in detail, in the semiconductor sensor 1 according to the present embodiment, the comb structure 13 is provided on the weight portion 11 and the comb structure 14 is provided on the support portion 12, and the comb structure is provided. The opposing surfaces of the bodies 13 and 14 are inclined surfaces 13a, 13b, 14a and 14b, and the inclination offset angle θ is determined so that the comb-tooth structures 13 and 14 overlap each other, thereby forming a stopper structure. I have to. For this reason, the weight unit 1 receives acceleration.
Even when 1 is displaced, the magnitude of the displacement is limited to the range until the comb structure 13 contacts the comb structure 14.

Therefore, even when an excessive acceleration due to a drop impact or the like is received, problems such as breakage of the beam portion 17 or occurrence of a misstep due to excessive displacement of the weight portion 11 do not occur. Thereby, the semiconductor sensor 1 which is strong against impact and easy to handle is realized. Also, since the inclination of the comb-tooth structures 13 and 14 is reversed in the L region and the R-region, the lateral stress generated when the inclined comb-tooth structures 13 and 14 come into contact with each other is canceled by both. And the reliability of the semiconductor sensor 1 is further improved.

The inclined surfaces 13a, 13b, 14a,
The stopper structure 14b can be easily formed by reactive ion etching performed by irradiating ions obliquely. Therefore, the semiconductor sensor 1 can be manufactured by a simple manufacturing process in which the number of times of photolithography is small. Therefore, the manufacturing cost is low, and problems due to the photomask alignment accuracy hardly occur. As a result, the semiconductor sensor 1 that can be provided at low cost and can be widely used is realized. By performing etching while applying a horizontal electric field to ions in reactive ion etching, oblique etching can be performed.

The above embodiment is merely an example, and does not limit the present invention in any way. Therefore, naturally, the present invention can be variously modified and modified without departing from the gist thereof.

For example, the semiconductor sensor 1 according to the above-described embodiment detects acceleration by a change in capacitance between the weight portion 11 and the substrate 10 (fixed portion).
Instead, the acceleration may be detected by detecting distortion by providing a piezo element in the beam portion 17. Also, the detectable mechanical quantity is not limited to acceleration. For example, by applying a voltage signal to the comb structure 14 and driving the weight portion 11 to vibrate, the angular velocity can be detected by detecting the Coriolis force applied to the weight portion 11.

In the above-described embodiment, the SOI wafer is used as the original substrate, and the upper semiconductor layer is processed to form the weight portion 11.
And the support portion 12 are formed. Instead, a polycrystalline silicon layer is formed on the thermal oxide film or the laminated oxide film by CVD or the like, and the polycrystalline silicon layer is processed to form the weight portion 1.
1 and the support portion 12 may be formed. Also,
The weight portion 11 and the support portion 12 are formed by diagonal reactive ion etching for forming the comb structures 13 and 14.
Are formed at the same time, but they may be formed by providing a separate etching step before or after. In addition, when the oblique etching of the R region is performed, the mounting direction of the wafer is the same as that of the etching of the L region, and the lateral electric field is set to the opposite polarity to obtain a symmetrical inclination. The mounting direction of the wafer may be reversed by 180 °, and the polarity of the lateral electric field may be the same as that in the etching of the L region. In addition, the planar shape of the weight portion 11 and the number of the anchor portions 16 and the beam portions 17 are also arbitrary.

[0036]

As is apparent from the above description, according to the present invention, by having the inclined first and second surfaces, a stopper structure for preventing excessive displacement of the weight portion and a simple structure are provided. A semiconductor sensor that can be manufactured by a manufacturing process and a manufacturing method thereof are provided. The problem caused by the lateral stress is also eliminated. This provides a semiconductor sensor that is highly reliable and has no manufacturing problems and can be used for a wide range of applications. Further, there is provided a method of manufacturing a semiconductor sensor capable of easily forming first and second inclined surfaces by obliquely incident reactive ions.

[Brief description of the drawings]

FIG. 1 is a plan view of a semiconductor sensor according to an embodiment.

FIG. 2 is a cross-sectional view showing a supporting portion of the semiconductor sensor.

FIG. 3 is a sectional view showing a weight portion of the semiconductor sensor.

FIG. 4 is a sectional view showing an anchor portion of the semiconductor sensor.

FIG. 5 is a sectional view showing a beam portion of the semiconductor sensor.

FIG. 6 is a sectional view showing a comb structure of the semiconductor sensor.

FIG. 7 is an enlarged view showing a cross-sectional shape of the comb tooth structure.

FIG. 8 is a view showing a comb structure in a contact state.

FIG. 9 is a cross-sectional view of an SOI wafer used for manufacturing a semiconductor sensor.

FIG. 10 is a diagram schematically illustrating an RIE apparatus for performing inclined etching.

FIG. 11 is a cross-sectional view showing the comb structure immediately after one-side etching.

FIG. 12 is a cross-sectional view showing a state where an oxide film is deposited.

FIG. 13 is a cross-sectional view showing a state where an oxide film is etched and flattened.

FIG. 14 is a cross-sectional view showing the comb structure with both sides etched.

FIG. 15 is a diagram illustrating the structure of a conventional semiconductor sensor.

FIG. 16 is a view showing a manufacturing process of a conventional semiconductor sensor.

FIG. 17 is a view showing a manufacturing process of a conventional semiconductor sensor.

[Explanation of symbols]

 Reference Signs List 1 semiconductor sensor 10 semiconductor substrate (fixed portion) 11 weight portion 13a, 13b inclined surface (second surface) 14a, 14b inclined surface (first surface) θ offset angle

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Masato Hashimoto 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (72) Inventor Yasunori Goto 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation ( 72) Inventor Atsuko Yokoyama 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation

Claims (4)

[Claims] 1. A semiconductor sensor having a fixed portion and a weight portion, wherein a dynamic quantity is detected by displacement of the weight portion with respect to the fixed portion, wherein the fixed portion has a predetermined offset angle with respect to the direction of the displacement. An inclined first surface is formed, a second surface facing the first surface is formed on the weight portion, and the second surface displaces the weight portion in the direction of the displacement. A semiconductor sensor, wherein the semiconductor sensor is arranged at a position capable of contacting the first surface. 2. The semiconductor sensor according to claim 1, wherein two pairs of said first surface and said second surface are provided, and the offset angles of each pair are opposite to each other with respect to the direction of said displacement. A semiconductor sensor, comprising: 3. The method of manufacturing a semiconductor sensor according to claim 1, wherein said fixing portion and said weight portion are formed, and said semiconductor layer is subjected to anisotropic etching at a predetermined offset angle with respect to a normal direction of said semiconductor layer. A method for manufacturing a semiconductor sensor, the method comprising: forming a first surface and a second surface by a tilt etching process. 4. The method of manufacturing a semiconductor sensor according to claim 3, wherein the inclined etching step is performed by reactive ion etching while applying a horizontal electric field.