Electromechanical element, electric circuit device and production method of those

An electromechanical element includes a mechanically movable element through a hollow formed on a substrate, and a plurality of holes formed in the movable element. In the electromechanical element, the plurality of holes are arranged such that at least two holes are in a same line, at least one hole is in another line located adjacent to the one line with at least two holes, and a distance between one of the holes arranged in the same line and the other hole located at the closest position from the one of the two holes arranged in the same line is longer than a distance between the holes adjacently arranged in the same line.

CROSS REFERENCES TO RELATED APPLICATIONS

The present invention contains subject manner related to Japanese Patent Application JP 2006-042987 filed in the Japanese Patent Office on Feb. 20, 2006, the entire contents of which being incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an electromechanical element, an electric circuit device and a method of fabricating the electromechanical element and the electric circuit device.

2. Description of the Related Art

A micro electromechanical element, or MEMS (Micro Electro Mechanical System) is used as a single element for a switch, filter and capacitor or the like, or installed on a common semiconductor substrate with a circuit element of another semiconductor elements or the like to form various electric circuit devices (e.g., see patent publication: Japanese Unexamined patent publication H9-162462).

The MEMS includes a movable element, or an actuator that performs a mechanical vibration or a required mechanical operation of displacement or the like, and is driven by an electrostatic or electromagnetic force or combination of the electrostatic or electromagnetic force or the like. In such MEMS, specifically in surface MEMS, the movable element is usually formed on a sacrifice layer, and a hollowed portion is formed by removing the sacrifice layer located under a movable portion of the movable element, by etching from a circumference of movable portion in a lateral direction, where mechanical operations such as a vibration and displacement can be performed in the hollow.

However, when a perfect hollow is formed under the movable element, later conducting steps of forming electrode, cleaning, drying, inspection of warping and dicing, or the like can be performed on the movable element, mechanical load may be imposed on the movable element. This may cause deformation of or damage to the movable element, thereby resulting in decrease in reliability and production of defective products.

For example, an Al (aluminum) electrode is widely used for an electrode that feeds electricity to the movable element. However, the Al electrode is formed after removing the sacrifice layer by etching since the Al is corroded with a concentrated fluoric acid used as an etching solution for the sacrifice layer. However, forming the Al electrode on the movable element floating in a hollow can impose a comparatively large mechanical load on the movable element, for example, the Al formation of entire surface, an entire surface coating of photoresist for forming a pattern with a required shape, and patterning by photolithography. Such mechanical load on the movable element may cause deformation of or damage to the movable element, which may result in reduction in reliability or production of defective products. Specifically, in a case in which the movable element includes a large area, accurately etching the sacrifice layer that is located under the movable element can be difficult when etching from a circumference to the center of the movable element. Further, since etching may take a long time, etching after the formation of electrode mentioned above may impose some effects on the movable element.

SUMMARY OF THE INVENTION

According to an electromechanical element, an electric circuit device and a method of fabricating the electromechanical element and the electric circuit device of embodiments of the present invention, effects on a movable element formed by etching the sacrifice layer, electrodes, or the like in the electromechanical element can be reduced, and the sacrifice layer can reliably be removed. The electromechanical element, an electric circuit device and a method of fabricating the electromechanical element and the electric circuit device according to embodiments of the present invention, improvement in the reliability and reduction in the occurrence rate of defective products can also be realized.

According to an electromechanical element of an embodiment of the present invention, there is provided an electromechanical element that includes

a mechanically movable element through a hollow formed on a substrate, and

a plurality of holes formed in the movable element, in which

the plurality of holes are arranged such that at least two holes are in a same line, at least one hole is in another line located adjacent to the one line with at least two holes, and a distance between one of the holes arranged in the same line and the other hole located at the closest position from the one of the two holes arranged in the same line is longer than a distance between the holes adjacently arranged in the same line.

An electric circuit device according to an embodiment of the present invention, there is provided an electric circuit device that includes

a mechanically movable element through a hollow formed on a substrate, and a plurality of holes formed in the movable element through which a sacrifice layer is etched, in which

the plurality of holes are arranged such that at least two holes are in a same line, at least one hole is in another line located adjacent to the one line with at least two holes, and a distance between one of the holes arranged in the same line and the other hole located at the closest position from the one of the two holes arranged in the same line is longer than a distance between the holes adjacently arranged in the same line.

According to an electromechanical element and an electric circuit device of embodiments of the present invention, since holes are formed in the movable element of the electromechanical element, not only can the sacrifice layer be etched from a circumference of the movable element, but the sacrifice layer can also be etched through the holes formed in the movable element. Further, since the holes are arranged in the movable element according to the above-described positional manner, pillar shaped or a wall shaped support portions for the movable element can be formed in the process of etching the sacrifice layer without forming any liquid pools.

According to a method of fabricating an electromechanical element of an embodiment of the present invention, there is provided a method of fabricating an electromechanical element including a mechanically movable element through a hollow formed on a substrate that includes the steps of:

forming a movable element through a sacrifice layer,

penetrating to form a plurality of holes in the movable element through which the sacrifice layer is exposed, and

performing at least a first etching and second etching on the sacrifice layer, in which

the first etching includes etching the sacrifice layer from a circumference of the movable element and from limbs of the holes in the movable element to form support portions for the movable element using residual portions of the sacrifice layer that are not etched from the circumference of the movable element and from the limbs of the holes in the movable element, and the second etching includes removing the residual portions of the sacrifice layer located under the movable element such that the resultant sacrifice layer can be in a movable condition.

According to a method of fabricating an electric circuit device of an embodiment of the present invention, there is provided a method of fabricating an electric circuit device includes the steps of:

forming a movable element through a sacrifice layer,

penetrating to form a plurality of holes in the movable element through which the sacrifice layer is exposed, and

performing at least a first etching and second etching on the sacrifice layer, in which

the holes in the movable element are arranged such that a distance between one of the holes arranged in the same line and the other hole located at the closest position from the one of the two holes arranged in the same line is longer than a distance between the holes adjacently arranged in the same line,

the first etching includes etching the sacrifice layer from a circumference of the movable element and from limbs of the holes in the movable element to form support portions for the movable element in a pillar shape or a wall shape using residual portions of the sacrifice layer that are not etched from the circumference of the movable element and from the limbs of the holes in the movable element, and

the second etching includes removing the residual portions of the sacrifice layer located under the movable element such that the resultant sacrifice layer can be in a movable condition.

According to a method of fabricating an electromechanical element and an electric circuit device of embodiments of the present invention, since holes or through-holes are preliminary formed in the movable element of the electromechanical element, the sacrifice layer can be etched from a circumference of the movable element, as well as etching through the holes formed in the movable element. As a result, the sacrifice layer, particularly the central portion of the sacrifice layer can effectively and reliably be removed by etching.

The etching may include at least two steps. A first etching includes a main etching step in which the sacrifice layer is efficiently removed using a high etch-rate etchant, and support portions for the movable element formed of the residual portions of the sacrifice layer is provided for reinforcing the movable element by selecting arrangement of the holes as described above. Any process having greater mechanical load on the movable element can be conducted in this state after the first etching accordingly. A second etching only includes removing part of the residual portions of the sacrifice layer.

As described above, according to an electromechanical element and an electric circuit device of embodiments of the present invention, since holes are formed in the movable element, not only can the sacrifice layer be etched from a circumference of the movable element, but the sacrifice layer can also be etched through the holes formed in the movable element. As a result, the sacrifice layer can reliably and rapidly be removed by etching to form the movable element having a large area, such as large-scale surface MEMS having more than 100 μm on a side. Further, since the holes are arranged in the movable element according to the above-described positional manner, pillar shaped or a wall shaped support portions for the movable element can be formed in the process of etching the sacrifice layer. Thus, since mechanical strength of the movable element can be maintained and deformation of and damage to the movable element can be prevented during the fabrication steps, reliability can be improved and defective products can be decreased.

According to a method of fabricating an electromechanical element and an electric circuit device according to embodiments of the present invention, the main etching is conducted without removing support portions that can mechanically support the movable element in the first etching step as described above. Therefore, deformation of or damage to the movable element can be prevented; for example, deformation due to mechanical load or damage to on the movable element caused by forming electrodes on the movable element can be prevented. As a result, reliability and a yield rate can be improved.

The hollow formed by selecting arrangement of the aforementioned holes in the first etching cannot be intercepted with the sacrifice layer remained as mechanical support portions in the second etching. Thus, corroding electrodes or the like with an etchant due to elongation of immersion time can also be prevented in the second etching.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiments of an electromechanical element, an electric circuit device and a method of fabricating an electromechanical element and an electric circuit device are described with referring to drawings. However, the present invention is not limited to the embodiments.

FIGS. 1A and 1Bare schematic sectional views of an electromechanical element1according to an embodiment of the present invention.

The electromechanical element1indicates a switch element including an electrostatic actuator that turns on or off using an electrostatic drive.

In the electromechanical element1, specifically, in the electrostatic switch element, an insulating layer3is formed on a substrate2, such as a crystal surface (100) forming a silicon semiconductor substrate surface, on which a fixed electrode4including an electrostatic actuator and a movable element5are formed, and the movable element5, one end of which is fixed on the substrate2with an anchor6to form a cantilever model, and the electrode4are formed such that the movable element5moves close to or away from the electrode4using an electrostatic drive.

Further, first and second signal lines7,8having respective fixed contacts7a,8aat the front ends are formed on the insulating layer3.

A movable contact5ais formed at an excessive end of the movable element5through an insulating layer9.

On the other hand, the first and second signal lines7,8having the respective fixed contacts7a,8aat front ends that turns on or off by the movable element5are formed on the insulating layer3of the substrate2.

A wiring10is formed on a fixed side of the movable element5from the insulating layer3of the substrate2, and a required electric charge is supplied to the movable element5through this wiring10, thereby carrying out electrostatic push and pull operations between the movable element5and the fixed electrode4. Consequently, the movable contact5amoves between the fixed contacts7aand8aformed at the end of the first and second signal lines7and8to carry out the on-off operation by the movable element5.

The insulating layer3may include a SiN (Silicon Nitride) layer with a thickness of 200 nm and SiO2(Silicon dioxide) layer with a thickness of 100 nm to form a laminated film, for example, and the insulating layer9may include SiN layer with a thickness of 100 nm.

In addition, the fixed electrode4may include P (phosphorous)-doped polycrystalline Si with a thickness of 150 nm, for example.

The movable contact5aand fixed contact8amay include Silicide thin film with a thickness of 100 nm.

The insulating film9includes a material for the sacrifice layer23described later, such as a SiN layer with a thickness of 100 nm that is corrosion-inhibiting against a SiO2etching solution.

Further, the anchor6may include an amorphous Si film with a thickness of 100 nm and the movable element may include the same amorphous Si layer with a thickness of 1000 nm.

The wiring10includes AlCu (Aluminum Copper) layer with a thickness of 500 nm, for example.

According to an embodiment of the present invention, a plurality of holes5h, each having such as circled or squared-shape, are formed in the movable element5.

FIG. 2is a plan view showing a basic configuration of holes5hin a movable element5of an electromechanical element according to an embodiment of the present invention.

In the holes5h, a distance “a” between two holes5h1and5h2located in the same line and a distance “b” between one of the two holes5h1and5h2and a hole5h3located at the closest position from the one of the two holes5h1and5h2are arranged such that the distance “a” is shorter than the distance “b”.

FIG. 3is a plan view showing a plurality of combination holes5has a basic configuration of holes5h1to5h3of a movable element according to an embodiment of the present invention.

Examples inFIGS. 2 and 3show examples showing an arrangement of the three holes as a combination. In the examples, the hole5hof the combination holes can be arranged such that the5his located at a vertex of an isosceles triangle.

FIG. 4is a plan view showing another example of configuration of holes5hof a movable element5according to an embodiment of the present invention.

In this example, the holes are arranged such that the distance “a” is shorter than the distance “b” as described above; however, the configuration of the combination holes form a right angled triangle instead of an isosceles triangle.

A width of the squared holes5hor an inner diameter of the circled holes5hmay be selected to have approximately 5 μm to 10 μm, and the distance “a” may be selected to have approximately 10 μm to 20 μm, and the distance “b” may be selected to have approximately 15 μm to 35 μm. A size of the hole5hand the distance between the holes5harranged are selected depending on rigidity required for a movable element finally formed as an actuator; however, the distance is selected to be as short the distance between the holes5has the rigidity allows. The size of the hole5his selected as small as possible in accordance with the viscosity of a chemical solution.

Next, a method of fabricating an electromechanical element according to an embodiment of the present invention is described accompanying a method of fabricating an electric circuit according to an embodiment of the present invention that includes this electromechanical element.

FIGS. 5 to 10are outline sectional views showing some steps of a method of fabricating an embodiment of the present invention; andFIGS. 11 to 16are outline plan views showing the steps of the method of fabricating the embodiment of the present invention that are useful to illustrate the outline sectional views. The same numerals corresponding to portions ofFIG. 1are given to the portions of theFIGS. 5 to 16.

In the embodiment, as is shown inFIG. 5A, another electric circuit element21or the like that configures an electric circuit device is formed on one of the main surfaces of a substrate2formed of a silicon semiconductor substrate by an ordinary method. A portion on which an insulated gate MOSFET (Metal Oxide Semiconductor Field Effect Transistor) formed is shown as a representative of the electric circuit element21in the drawing.

For example, surface insulating layers22are formed on both surfaces of the silicon semiconductor substrate of the substrate2by surface thermal oxidation, on which an insulating layer3formed of SiN with a thickness of 300 nm is formed by CVD (Chemical Vapor Deposition) on the surfaces.

An anchor6that supports a movable element of an electromechanical element described inFIG. 1is formed on the insulating layer3on which the electromechanical element is formed as a target of the substrate2. The anchor6may be formed by having a high resistance polycrystalline Si layer or SiN layer with undoped impurities once formed on the entire surface of the insulating layer3by CVD, and then having the high resistance polycrystalline Si or SiN layer pattern-etched in a limited extent at predetermined position by the lithography.

As is shown inFIGS. 5B and 11, a fixed electrode4and wiring of first and second signal lines7,8that are arranged to face a movable element described inFIG. 1are formed on the insulating layer3. For example, the wiring is formed by forming an impurities-doped polycrystalline Si layer or metal layer on an entire surface by the sputtering or the like, and then is patterned by lithography.

A sacrifice layer23may include Sio2, for example. The a insulating layer9may be formed of SiN that has excellent selectability for etching and that is not corroded or difficult to be corroded by a fluoride acid solution used for the sacrifice layer23as the etching solution.

As is shown inFIG. 6A, the sacrifice layer23is formed to cover an anchor6, a fixed electrode4and wiring of first and second signal lines7,8or the like. The sacrifice layer23is formed on an entire surface (not shown), and then planarized by performing etchback by CMP (Chemical Mechanical Polish) until an upper end of the anchor6is exposed.

As is shown inFIGS. 6B and 12, a movable element5is formed on the planarized surface of the sacrifice layer23such that the movable element5extended from an upper end surface of the anchor6to the vicinity of the front end of signal lines7,8are not interfere with an arrangement portion of the fixed electrode4. The movable element5may have an impurities-doped polycrystalline Si layer with conductivity formed once on the entire surface, and then form the above-described required pattern by photolithography.

As is shown inFIGS. 7A and 13, a movable contact5aformed of Au alloys or Silicide described inFIG. 1is formed on the sacrifice layer23such that the movable contact5ais interposed between the contacts7aand8alocate at respective front ends of the first and second signal lines7,8that are faced each other. The sacrifice layer23is etched by isotropic etching.

As shown inFIGS. 7B and 14, an insulating layer9is formed on a front end of the movable element5and a movable contact5avia the insulating layer9such that an excessive end of the movable element5and the movable contact5aare mechanically connected.

For example, the insulating layer9is once formed on an entire surface, which is then performed patterning by photolithography.

As shown inFIGS. 8A and 15, a plurality of holes5hare formed in the movable element5by the photolithography. The first etching is then performed subsequently. The etching is performed from portions where the sacrifice layer around the holes5hand movable element5are exposed outside by wet-etching using a high concentration etching solution, such as a fluoric acid. The sacrifice layer23is etched by isotropic etching.

Thus, as shown inFIG. 8B, the hollowed portions23hare formed by removing the sacrifice layer using a face-directional etching which begins with the peripheral portion of the movable element5and the holes5h, and proceeds into under the peripheral portion of the movable element5and under limbs of the holes5h; while etching is not performed between the hollowed portions23h, and residual portions of the sacrifice layer remains forming support portions23sthat support the movable element5having a pillar shape or a wall shape.

As is shown inFIG. 9A, an aluminum wiring layer24forming the wiring10that supplies power to the movable element5shown inFIG. 1is formed on an entire surface by sputtering or the like.

Then, as shown inFIGS. 9B and 16, wiring layer24is etched with a required pattern to form the wiring10.

The wiring10may be formed by patterned etching using photolithography. As shown inFIG. 9A, a photoresist25is formed on the portion where the wiring10of the wiring layer24is formed. The photoresist25may be formed by entire surface coating, pattern exposure and development. Then, the photoresist25is removed by wetetching using the Al wiring layer24as a mask that does not substantially corrode the movable element5, insulating layers9and3or the like, thereby forming the wiring10having the required pattern.

A comparatively large weight due to such as formation of the photoresist25and a mechanical load such as a pressure during the coating is imposed on the movable element5. However, according to a method of fabricating an embodiment of the present invention, since the aforementioned support portions23sremains under the movable element5, deformation of or damage to the movable element5may be prevented.

It should be noted that in the formation of the above wiring10, the Al wiring layer24, is accumulated in the inner limbs of the holes5hand on the insulating layer3through the holes5hduring sputtering of the wiring layer24such as Al layer on the entire surface; however, the amount of deposition are very small, therefore the deposition may be removed during the wet-etching used for the patterning that forms the above wiring10.

An electric circuit device30according to an embodiment of the present invention is fabricated by the following steps:

forming a movable contact5aat the front end of the substrate2where the circuit element21is formed;

forming a cantilevered movable element5, one end of which the movable contact5ais supported by an anchor6; and

forming an electromechanical element1that performs on or off operation between the fixed contacts7aand8aof the first and second signal lines7,8by the push or pull operation using electrostatic force between the movable element5and the fixed electrode4, for example.

As is mentioned above, according to an embodiment of the the present invention, the first and second etching steps are performed. In the first etching step, most of the sacrifice layer23may be removed with fluoride acid. In the second etching step, the second etching can be carried out on residual portions of the sacrifice layer using a comparatively light-etching with buffered fluoride acid in comparatively short time.

As mentioned above, according to an embodiment of the present invention, first etching step, the removal of the sacrifice layer23is performed by etching proceeded from the outer edge of a movable portion other than a fixed portion with the anchor6of the movable element5and by etching proceeded from the holes5h; however, the first etching is stopped when portions of the sacrifice layer23remain unetched to form the support portions23shaving a pillar shape or a wall shape.

In this case, if the support portions23sformed by the residual sacrifice layer23encloses some of the hollows23h, and the path of the etching solution is blocked against the circumference of the movable element to form a closed pattern the liquid pool of the etching solution occurs in this portion and the etching solution can only be supplied to the holes5h. Thus, since the etching solution is comparatively decreased, etching progress is drastically lowered. As a result, in the second etching step, the sacrifice layer cannot be removed completely or the electrode or the like may be corroded due to elongation of the etching time.

According to an embodiment of the present invention, the shape of the support portions23smay form a closed pattern to prevent occurrence of the liquid pool. As described inFIGS. 2 to 4, the occurrence of liquid pool is prevented by arranging the holes5hsuch that the relationship between a distance “a” between two holes5h1and5h2adjacently arranged in the same line is shorter than a distance “b” between one of the two holes5h1,5h2and one hole5h3arranged in another line having the closest position from one of the two holes5h1,5h2. The three holes correspond to respective vertices of an isosceles triangle or a right angled triangle.

The following describes details of the above.

FIGS. 17 to 20are schematic sectional views showing the following configuration. A plurality of holes5hin each movable element5are arranged in respective lines with a predetermined interval “a”. Specifically, two holes5hin one line arranged with a predetermined interval “a” and one hole5hin another line located adjacent to the line with the same interval “a” are arranged with a distance of “a”/2 shifted in the row-direction, and the both lines with respective holes are alternately arranged. In this configuration, the two of holes5hadjacently arranged in the same line and the one hole5hlocated between the two hole in the other line are arranged such that the two holes in the same line and the one hole in the other line respectively correspond to vertices of an isosceles triangle. More specifically, a basic configuration of holes in the two lines alternately arranged inFIGS. 17 to 20shows the basic configuration in the reverse direction inFIG. 2.

FIG. 17shows the above-mentioned cantilevered configuration in which a movable element5is supported by an anchor6at one side, and the aforementioned row-direction of the holes5hof the movable element5indicates the direction along the side where the anchor is arranged.

In addition, in an embodiment shown inFIG. 18, two anchors6are arranged at two sides of the movable element that are faced to each other, and further, in an embodiment shown inFIG. 19, anchors6are arranged at three sides of the movable element.

Specifically, an etchant cannot be entered from circumferences of the portions where the anchors6are arranged, an anchor6is not arranged on at least one portion of at least one side of the movable element5.

Further,FIG. 20shows two types movable elements5A and5B having different shapes. This indicates a combination of two types of the movable elements, namely, an electromagnetic type and an electrostatic type.

Etching of the sacrifice layer23formed under the movable element5is performed by etching from holes5hand by the etching from the open side of the movable element5where the anchor6is not arranged; however, etching from centers of the holes5his circularly proceeded in the isotropic direction, thereby forming a hollowed portion23haround each hole5h.

In this case, when the first etching is stopped after a predetermined time is elapsed by selecting a distance “a” between the holes5hadjacently arranged in the same line, a distance “c” between the adjacent two lines and a distance “b” between two holes5harranged in adjacent lines and selecting etching condition or the like, etching is circularly proceeded from centers of the holes5harranged in the same line in the isotropic direction, and the portions of the hollowed portion23hare merged to form a communication hollowed portion23h.

Then, at least one end of the communication hollowed portion23his arranged such that the end is communicated outside at the side where an anchor6of the movable element5is not arranged.

For example, both ends of the communication hollowed portion23hcan directly communicate outside as shown inFIG. 17.

Then, support portions23sformed of walls by using the residual portion of the sacrifice layer23are provided between those connected hollowed portions23hformed in the row-direction as a main extended direction.

Thus, the support portions23shaving a wall shape are formed by using the residual portion of the sacrifice layer23located under the movable element5, the movable element5is firmly reinforced in comparison with the support portions23shaving a pillar shape, for example.

The hollowed portions23hformed in the etching step may directly be opened to the side of the movable element5, or formation of closed portions can be prevented by forming the hollowed portions during etching from a circumference of the movable element5, thereby preventing occurrence of a liquid pool.

In an embodiment ofFIG. 20, both ends of the communication hollowed portions23hinclude the anchors6; however, an etchant can be entered and etching is proceeded by having at least one side of the movable element5opened. Accordingly, one end of the communication hollowed portion23hcan directly be opened outside of the movable element5, or can be opened outside by communication with etching portions proceeded from the open side of the movable element5.

According to an embodiment of the present invention, formation of etching pools in etching sacrifice layer can be prevented by forming a plurality of holes5hwith a specific arrangement in the movable element5.

FIGS. 21A,21B and22A,22B are schematic plan views showing arrangements of holes5hin the movable element5that do not refer to the embodiments of the present invention.

Specifically,FIGS. 21A,21B and22A,22B show the residual portions of the sacrifice layer23or patterns of the support portions23sformed in the first etching when the equation “a=b” is applied to distances “a” and “b” between the adjacently arranged holes.FIGS. 21A and 21Bshow configurations in which the holes5hare arranged at respective corners of a square, andFIGS. 22A and 22Bshow configurations in which the holes5hare arranged in a staggered arrangement. If the support portions23sare formed with a wall shape, the hollows23hformed through the holes5hare independently separated by the support portions23s, thereby forming liquid pools as is shown inFIGS. 21A and 22A. Or, as shown inFIGS. 21B and 22B, if the support portions23sfare formed with a pillar shape, since the adjacent hollowed portions23hcan merely be communicated through small regions of point-contacts or line-contacts, the liquid pool is substantially formed.

According to a configuration and a method of the embodiments of the present invention, the drawbacks of this kind may be prevented.

According to an electromechanical element, an electric circuit device and a method of fabricating an electromechanical element and an electric circuit device of an embodiment of the present invention, a plurality of holes5hare arranged in the movable element with a specific arrangement pattern. According to the fabrication, the sacrifice layer can be removed with support portions, that is, any process having greater mechanical load on the movable element can be conducted with support portions in the first and second etchings. For example, in the fabrication of a large-scale movable element, since deformation of and damage to the movable element can be prevented during the fabrication steps, reliability can be improved and a yield rate can be improved.

The formation of etching pools can be prevented in forming support portions of the sacrifice layer, etching of the sacrifice layer can efficiently conducted. Further, etching can be conducted using a low etch rate etchant in a short period of time, corroding electrodes or the like with an etchant in the second etching can efficiently be prevented.

It should be noted that the embodiments shown in the drawings are the cases in which the holes that are penetrated to form in the movable element5are a square shape; however, the shapes of the holes are not limited to a square shape. The holes may be a polygon such as a circle, triangle or the like. without limiting it to this shape. In practice, when the sacrifice layer23is etched through the penetrated holes, there is no effect on the removal of the sacrifice layer23, and hence formation of the holes can be easier for masking in the photolithographic step when using a polygon shape such as a square shape.

In addition, it is apparent that an electromechanical element, electric circuit and a method of fabricating the electromechanical element and the electric circuit according to the embodiments of the present invention are not limited to the configuration including a movable element, and various movable elements can be applied to an electromechanical element and electric circuit and a method of fabricating the electromechanical element and the electric circuit. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and alterations may occur depending on design requirements and other factors insofar as they are within the scope of the appended claims or the equivalents thereof.