KR20100033129A - Acoustic-signal/electric-signal converting device and method for fabricating the same - Google Patents

Abstract

PURPOSE: An acoustic signal to electric signal converting device and a manufacturing method thereof are provided to improve a vibrating function by flexibly operating the thinning process of a vibration plate. CONSTITUTION: A back chamber(BC) is formed in a substrate(101). A vibration plate(102) is formed on the substrate in order to cover up the back chamber. A variable electrode(103) is formed on the suspending area of the vibration plate corresponding to the back chamber. A cover plate(105) defines an acoustic hole and an air gap. The cover plate is formed in the vibration plate in order to cover up the variable electrode. The cover plate operates as the fixed electrode corresponding to the variable electrode. The cover plate is formed by an electroplating process utilizing a polymer based sacrificial layer.

Description

Acoustic-signal / electric-signal converting device and method for fabricating the same

The present invention relates to a negative / electric conversion element and a method for manufacturing the same, and more particularly, <measurement for changing a sacrificial layer serving as a base matrix of cover plate formation to a polymer-based material which is easy to generate / remove at low temperature>, <Measurement of changing the cover plate formation procedure to an electroplating procedure capable of proceeding at low temperatures>, <Additional installation of an adhesive barrier dimple to block the adhesion of the diaphragm and the cover plate to a part of the cover plate> , <Additional disposition of insulating layer at the contact interface between cover plate and substrate>, <Measurement of forming back chamber through double process such as Deep Reactive Ion Etching (Deep-RIE) and Anisotropic Etching > And the application of elasticity, etc., through this, one-step manufacturing process of negative / electric conversion element and signal processing chip, problem caused by adhesion of cover plate and diaphragm By effectively realizing the blocking, reducing the amount of parasitic capacity, and maximizing the size of the back chamber, on the producer side, the damage caused by the dual manufacturing environment of the negative / electric conversion element and the signal processing chip, and the adhesion of the cover plate and the diaphragm The present invention relates to a negative / electric conversion element and a method of manufacturing the same, which can guide the damage, the damage caused by the increased amount of parasitic capacitance, and the damage caused by the reduction of the back chamber.

In recent years, as the related technologies of various electronic devices such as information and communication devices, sound devices, etc. have made rapid progress, the demand for sound / electric conversion elements for converting acoustic signals into electric signals has also increased rapidly. It shows a trend.

Typically, such a conventional negative / electric conversion element, for example, a MEMS type micro / electro-electric conversion element 10 has a variable electrode 15, as shown in FIG. With the diaphragm 12 and the diaphragm 12 covered, the acoustic hole 14 and the air gap (AG) are provided / formed, and the fixed electrode corresponding to the former variable electrode 15 is provided. While supporting the cover plate 13, the diaphragm 12, the cover plate 13, and the like, a back chamber (BC) is formed / defined to back the diaphragm 12 and the variable electrode 15. Substrate 11 or the like suspended on the chamber BC has a configuration in which organically combined, in this situation, the sound is introduced from the outside, the sound is the sound hole 14, air described above When flowing through the gap AG, the back chamber BC, etc., it plays a role of converting and generating a corresponding acoustic signal into an electrical signal.

At this time, the producer side proceeds with a chemical vapor deposition process (CVD process), such as having a material such as oxide, nitride, polysilicon on the diaphragm 12 (Sacrificial layer: not shown) ), The sacrificial layer is used as a base matrix to deposit a raw material such as polysilicon, and then the sacrificial layer is removed to define an air gap AG. The cover plate 13 is formed.

Meanwhile, a signal processing chip (not shown), such as a CMOS chip, which is combined with the negative / negative conversion element 10 in the same circuit board as one independent package, is added to the periphery of the negative / negative conversion element 10. Is placed.

In this case, the signal processing chip is a cover plate of the negative / electric conversion element 10 via an electrical connection means such as a wire (of course, the type and configuration of the electrical connection means can be variously modified depending on the situation). (13) and the diaphragm 12 and the like to form a series of electrical connection, in this situation, <the role of supplying the operating power to the negative / pre conversion element 10 side>, <negative / pre conversion element 10 After the subsequent processing of the electrical signal converted and generated by the), the role of delivering the electrical signal after the subsequent processing to the electronic device to which the negative / pre-conversion device 10 belongs> and the like.

Of course, since the signal processing chip is arranged in a separate package in the same circuit board as the negative / pre conversion element 10, the signal processing chip 10 and the signal processing chip may be connected to the circuit board. If it is possible to manufacture in one-step process at once, manufacturers can greatly reduce the overall manufacturing cost including the packaging process, for example, the process cost is greatly reduced, and the process efficiency is greatly increased. This can enjoy the effect very effectively.

Furthermore, if the &quot; one-step processing of the signal processing chip and the negative / pre conversion element 10 > becomes possible, the manufacturer can integrate the signal processing chip into the negative / pre conversion element 10 without any problems. In this way, it is possible to flexibly enjoy the excellent effect that the size of the package is drastically reduced, as well as through the single integration of the signal processing chip and the negative / electric conversion element 10, the unnecessary unnecessary electrical connection means such as wires. This can be easily removed, providing the flexibility to enjoy the outstanding effect of significantly improving the overall performance of the device.

However, as described above, under the conventional regime, the cover plate 13 belonging to the negative / electric conversion element 10 is a procedure that can be performed only at a very high temperature of 600 ° C. or higher, for example, <oxide, A process of forming and removing a sacrificial layer such as nitride and polysilicon at a high temperature (e.g., a CVD procedure)>, <a process of depositing a raw material such as polysilicon on a sacrificial layer at a high temperature (e.g., an LPCVD procedure)> If the manufacturer wants to manufacture the negative / electric conversion element 10 and the signal processing chip together in a one-step process in the same circuit board without any action on the part of the manufacturer, On the side, the <damage in which the signal processing chips that are combined and arranged on the circuit board due to the thermal shock due to the manufacture of the cover plate 13 is greatly damaged> cannot be avoided. Unless action is taken, the producer side cannot realize the one-step manufacturing process of the audio / electric conversion element 10 and the signal processing chip at all despite the aforementioned advantages.

Of course, under such a situation that the <one-step manufacturing process of the negative / pre conversion element 10 and the signal processing chip> is impossible, the producer side separates the negative / pre conversion element 10 and the signal processing chip from each other. As it is forced to manufacture separately through the process, the process cost increase, process efficiency decrease, performance degradation problem, and package size increase problem are inevitably suffered. As a result, consumers (negative / electric conversion The consumer who purchases / consumes the element 10, including the consumer who purchases / consumes the electronic device incorporating the negative / electric conversion element 10) also has several serious problems such as an increase in the price of the product and an increase in the size of the product. The damage is inevitable.

On the other hand, under the conventional sound / electric conversion element 10 system as described above, external sound is introduced through the sound hole 14 formed in the cover plate 13, and the sound passes through the air gap AG. In the case of flowing, the diaphragm 12 is compressed by a certain size by the sound pressure due to the sound, and eventually causes an operation of rapidly vibrating in the direction of the back chamber BC.

Of course, in such a situation, in general, since the diaphragm capable of smoothly performing the above-described vibration operation can be evaluated as a better quality diaphragm, in the conventional producer side in thinning the thickness of the diaphragm 12, Much effort is being made.

However, if the thickness of the diaphragm 12 is made too thin, the function as the vibrating body imparted to the vibrating plate 12 can be greatly improved. In this case, the cover plate 13 and the substrate ( In the area A where 11) is in contact with each other, the overall insulation thickness is greatly reduced, so that the damage inevitably caused a large parasitic capacitance is inevitable.

Of course, in this situation, the <parasitic capacitance generated at the contact portion A of the cover plate 13 and the substrate 12> may cause a decrease in sensitivity, an unnecessary mass trapping of ambient noise, and a sound / electric conversion element ( 10) and the communication between the signal processing chip inevitably acts as a cause, and eventually, the function of the sound / pre-conversion device 10 is greatly reduced.

Furthermore, under the conventional regime, since the diaphragm 12 maintains a relatively large area compared with its rigidity and forms a structure which is suspended in the air based on the back chamber BC, it is called surface force. It is inevitable to show a very sensitive response to a variable, and as a result, if a humid environment is created during manufacture / use of the negative / pre-conversion device 10, or overcurrent occurs during operation of the negative / pre-conversion device 10. If a harsh environment is created, it may fail to maintain its own original position and cause serious defects to stick to the cover plate 13 side.

Of course, in such a poor adhesion state of the diaphragm 12, on the negative / electric conversion element 10 side, for example, <the variable electrode 15 is in contact with the cover plate 13, an unnecessary electrical short occurs> Various serious problems can not be avoided, and eventually, they are forced to take the damage that their sound / electric conversion ability is greatly reduced.

Meanwhile, under the conventional system, the back chamber BC formed / defined using the substrate 11 as a base matrix is etched to the inside of the substrate 11 by an anisotropic etching process using an etching solution such as KOH. In this manner, the diaphragm 12, the variable electrode 15, and the like are formed on the substrate 11, and the &quot; roles as the sound path of the sound / electric conversion element 10 &quot; Role of defining the effective vibration area>.

In this case, the back chamber BC occupies the main flow path of the inflow sound along with the air gap AG, and further defines the effective vibration area of the diaphragm 12. The size of BC) is a very important factor in determining the overall sound / pre conversion quality of the sound / pre conversion element 10.

However, despite the fact that the size of the back chamber BC is a very important factor in determining the superiority of the negative / pre-conversion quality, the conventional producer uses an etchant such as KOH without any action. The anisotropic etching process is performed only once (assuming that no other minor addition process is performed) to form the back chamber BC. Of course, in this case, the overall profile of the back chamber BC is determined by the substrate ( 11) according to the crystal direction of the silicon constituting, inevitably suffers the problem of inclining inward to form a certain angle α1, α2, after all, the overall size (scale) of the back chamber BC and The effective vibration area of the diaphragm 12 formed thereon is inevitably reduced as much as the back chamber BC is inclined along the angles α1 and α2.

Of course, under this problem, when the overall size (scale) of the back chamber BC is greatly reduced, the back chamber BC is thus given a function of <the role of sound tube> and <the vibration plate 12 given to it. The role of maximizing and defining the vibration area> cannot be normally performed, and as a result, the sound / electric conversion quality of the sound / electric conversion element 10 is inevitably lowered.

Therefore, an object of the present invention is to <measure to change the sacrificial layer, which is the base matrix of the cover plate formation, to a polymer-based material that is easy to generate / remove at low temperatures>, and to allow the process of forming the cover plate to be processed at low temperatures. Measures to change to electroplating procedure>, <Addition of adhesive barrier dimples to block adhesion of the diaphragm and cover plate to part of cover plate>, <Insulation reinforcement at contact interface between cover plate and board Additional arrangement of insulation layer>, <action of forming back chamber through deep process such as Deep-Reactive Ion Etching (Deep-RIE), anisotropic etching>, etc. One-step manufacturing process of all conversion devices and signal processing chips, problem prevention due to adhesion of cover plate and diaphragm, reduction of parasitic capacity, back chamber size By effectively realizing conversations, on the producer side, damages due to the dual manufacturing environment of negative / electric conversion elements and signal processing chips, damages due to adhesion of cover plates and diaphragms, damages caused by increased generation of parasitic capacity, and The guide is to help avoid damage caused by the reduction of the size of the chamber.

Other objects of the present invention will become more apparent from the following detailed description and the accompanying drawings.

In order to achieve the above object, in the present invention, a back chamber is defined, a diaphragm formed on the substrate so that the back chamber is covered, and a suspending area of the diaphragm corresponding to the back chamber. And a cover plate formed on the diaphragm so as to cover the variable electrode while defining the formed variable electrode, the acoustic hole, and the air gap, and serving as a fixed electrode corresponding to the variable electrode, wherein the cover plate is polymer-based. Disclosed is a negative / electric conversion element formed by an electroplating process using a sacrificial layer.

In another aspect of the invention, forming a diaphragm on the front of the substrate, forming a variable electrode on the diaphragm, defining and forming a back chamber on the back of the substrate, the cover of the diaphragm Forming a sacrificial layer of a polymer series on a region to be formed of a plate, forming a seed layer on a diaphragm including the sacrificial layer, and forming an acoustic hole on the seed layer And forming a pattern mask for defining an adhesive blocking dimple and a cover plate, and using the pattern mask as a plating blocker, and performing an electroplating process based on the seed layer to form the acoustic hole and the adhesive blocking dimple. Forming a cover plate surrounding the sacrificial layer, removing the pattern mask, and then selectively removing the seed layer And opening the acoustic hole, and removing the sacrificial layer through the acoustic hole to define an air gap in the cover plate. It starts.

In the present invention, the <measurement of changing the sacrificial layer, which is the base matrix of the cover plate formation, to a polymer-based material which is easy to generate / remove at low temperatures>, and <the process of forming the cover plate is an electroplating procedure capable of proceeding at low temperatures. Action to change>, <Addition of adhesive blocking dimple to block adhesion of the diaphragm and cover plate to part of cover plate>, <Insulation layer for strengthening insulation at contact interface between cover plate and board In the embodiment of the present invention, the present invention provides a method of additionally arranging an additional structure>, and <a method of forming a back chamber through a dual process such as Deep Reactive Ion Etching (RIE) and anisotropic etching>. Manufacturer's one-step manufacturing process of negative / electric conversion element and signal processing chip, blocking problem caused by adhesion of cover plate and diaphragm, parasitic use It is possible to realize the reduction of the amount of generation and the maximization of the size of the back chamber, and finally, the damage caused by the dual manufacturing environment of the negative / electric conversion element and the signal processing chip, the damage caused by the adhesion of the cover plate and the diaphragm, and the parasitic capacity. Damage due to the increase in the amount of, the damage due to the scale of the back chamber can be easily avoided.

Hereinafter, with reference to the accompanying drawings, it will be described in more detail the negative / electric conversion element and its manufacturing method according to the present invention.

As shown in FIG. 2, the negative / pre-electric conversion element 100 according to the present invention, for example, a MEMS type micro-electro-mechanical system type negative / pre-electric conversion element 100 may include a substrate 101 such that the back chamber BC is covered. The acoustic plate 102 formed on the cover, the variable electrode 103 formed on the suspending area of the vibration plate 102 corresponding to the back chamber BC, and the diaphragm 102 are covered with sound The cover plate 105, the diaphragm 102, the cover plate 105, and the like, which serve as a fixed electrode corresponding to the variable electrode 103, are provided / formed with the hole 106 and the air gap AG. While supporting, the back chamber BC is formed / defined, and the diaphragm 102 and the substrate 101 for suspending the variable electrode 103 on the back chamber BC are organically combined. Done. In this case, as will be described later, the cover plate 105 uses a sacrificial layer 120 (see FIGS. 3H to 3O) as a base matrix to undergo a series of formation procedures.

Under such a configuration, when external sound is introduced through the sound hole 106 formed in the cover plate 105, and this sound flows through the air gap AG, the diaphragm 102 causes sound pressure due to the sound. The compression chamber is subjected to a certain size, thereby causing an operation of rapidly vibrating in the direction of the back chamber BC. Consequently, under such vibration operation on the diaphragm 102 side, the back chamber disposed at the bottom of the diaphragm 102. On the BC side, a certain amount of pressure is rapidly applied.

Of course, since the back chamber BC forms a series of closed spaces, which are closed to the outside, in combination with a circuit board (not shown) provided with the negative / previous conversion element 10, When a negative pressure is applied, a change in internal pressure of the back chamber BC causes a change in internal pressure, and a repulsive force of a predetermined magnitude against the previous sound pressure can be rapidly applied to the diaphragm 102, and in this situation, the diaphragm 102 ) Is also bounced back by the repulsive force on the back chamber BC side, so that the operation of vibrating in the direction of the cover plate 105 can be quickly taken.

As a result, under repeated processes of this mechanism, the potential between the cover plate 105 serving as the fixed electrode and the variable electrode 103 formed on the vibration plate 102 changes rapidly in response to sound. As a result, in this situation, on the variable electrode 103 side formed on the diaphragm 102, it is possible to quickly convert and generate the sound introduced through the acoustic hole 106 into an electrical signal.

Subsequently, the electrical signal thus converted and generated is quickly transmitted to the signal processing chip through an electrode rod 104 electrically connected to the variable electrode 103 and an electrode pad 109 electrically connected to the electrode rod. You will go through the procedure.

In this case, the signal processing chip, for example, the CMOS chip, is arranged in the same circuit board as the negative / electric conversion element 100, and forms an independent package, and electrical connection means such as wires (of course, such electrical connection The type and configuration of the means can be variously modified depending on the situation) and the cover plate 105 of the negative / electric conversion element 100, the diaphragm 012, etc. In this situation, <the role of supplying the operating power to the negative / pre-electric conversion element 100>, <the electrical signal converted and generated by the negative / pre-electric conversion element 100 After the subsequent processing, the role of transferring the post-processed electrical signal to the electronic device to which the negative / previous conversion element 100 belongs is variously performed.

Of course, as mentioned above, since the signal processing chip is arranged in a single independent package in the same circuit board as the negative / pre conversion element 100, the signal with the negative / pre conversion element 100 If the processing chip can be manufactured in one-step process in the circuit board at the same time, the producer side can greatly reduce the overall manufacturing process including the packaging process, for example, the process cost is greatly reduced, In addition to being able to effectively enjoy the advantages of greatly increasing process efficiency, the signal processing chip can be integrated into the negative / pre conversion device 100, thereby flexibly providing an excellent effect of dramatically reducing the size of the package. It is possible to enjoy, and furthermore, through a single integration of the signal processing chip and the negative / electric conversion element 100, unnecessary electrical connection such as <wire By stage> the easily able to be removed, it is possible to enjoy excellent effect also allows flexibility in the overall performance of the device is significantly improved.

In such a sensitive situation, in the present invention, the material of the sacrificial layer 120 (see FIGS. 3H to 3O) serving as a base matrix for forming the cover plate 105 may be produced even at a low temperature (eg, room temperature to about 120 ° C.). A method of changing to a polymer-based material that is easy to remove, for example, photoresist, paralyne, phosphosilicate glass, and the like, and the formation of the cover plate 105 Flexible measures are taken to change the procedure to an electroplating process, which allows the process to proceed even at low temperatures (eg from room temperature to 100 ° C).

Of course, when the material of the sacrificial layer 120, the formation method of the cover plate 105, etc. are remarkably improved, the process proceeds in a low temperature environment (for example, room temperature ~ 120 ℃) is possible, Even if the pre-conversion device 100 and the signal processing chip are manufactured together in a one-step process in the same circuit board, the signal processing chip disposed on the circuit board is damaged by thermal shock, etc. Can be easily avoided, and finally, the manufacturer can naturally realize the <one-step manufacturing process of the sound / electric conversion element 100 and the signal processing chip>, thereby producing the entire manufacturing process including the packaging process. The process can be simplified, and as a result, for example, it is possible to effectively enjoy the advantages of greatly reducing the cost of the process and the advantage of greatly increasing the process efficiency.

Naturally, under the situation of <one-step manufacturing process of the audio / electric conversion element 100 and the signal processing chip> according to the present invention, the producer side may insert the signal processing chip into the negative / electric conversion element 100 without any problem. By being able to integrate, it is possible to flexibly enjoy the excellent effect that the size of the package is drastically reduced, and at the same time, through the single integration of the signal processing chip and the negative / electric conversion element 100, Unnecessary electrical connections can be easily removed, providing the flexibility to enjoy the extraordinary effect of significantly improving the overall performance of the device.

As a result, under the implementation environment of the present invention, the consumer (including the consumer who purchases / consumes the negative / electric conversion element 10 and the consumer who purchases / consumes the electronic device in which the negative / electric conversion element 10 is embedded) is a product. The price can be reduced, the product performance can be improved, and furthermore, the product size can be easily enjoyed.

On the other hand, under the system of the sound / electric conversion element 100 according to the present invention, as described above, external sound is introduced through the sound hole 106 formed in the cover plate 105, and the sound is air gap AG. In the case of flowing through), the diaphragm 102 is compressed by a certain size by the sound pressure due to the sound, thereby causing an operation of rapidly vibrating in the direction of the back chamber BC.

Of course, in such a situation, as described above, in general, since a diaphragm capable of smoothly performing a vibration operation can be evaluated as a diaphragm of better quality, it is possible in many aspects to thinner the thickness of the diaphragm 102. Can be advantageous.

However, if the thickness of the diaphragm 102 is excessively thinned, in the area A where the cover plate 105 and the substrate 101 are in contact with each other at the producer side, the overall insulation thickness is greatly reduced, resulting in a large parasitic capacitance. This inevitably caused damage is inevitable.

In this sensitive situation, as shown in FIG. 2, the present invention induces a reduction in the amount of parasitic capacitance generated on the upper portion of the diaphragm 102 except for the support region of the diaphragm 102 (that is, the back chamber BC forming region). In order to further reduce the parasitic capacitance-inducing insulating layer 108, for example, SiO ₂ layer.

Of course, under the additional formation and arrangement of the parasitic capacitance-inducing insulating layer 108, for example, SiO ₂ layer, the insulating thickness between the cover plate 105 and the substrate 101 is <only the vibration plate 102 alone. Compared to the case where it is formed>, the parasitic capacitance generated at the portion A where the cover plate 105 and the substrate 101 are in contact with each other can be greatly reduced compared to the conventional case.

As a matter of course, under the implementation environment of the present invention, the producer side can freely thin the thickness of the diaphragm 102 to significantly improve the function as the vibrating body imparted to the vibrating plate 102, while insulated from the parasitic capacitance induction. By utilizing the combination of the layer 108 and the diaphragm 102, the insulation thickness between the cover plate 105 and the substrate 101 can be stably maintained, resulting in the overall conversion of the negative / electric conversion element 100. It will naturally maximize the sound / electric conversion quality.

At this time, as shown in Figure 2, the parasitic capacitance reducing induction insulating layer 108 of the present invention, the entire region of the diaphragm 102, that is, a vibration-sensitive region, that is, <the support region of the vibrating plate 102 (that is, Except for the back chamber (BC forming region)>, the diaphragm 102 has a structure which partially occupies only the remaining part of the region. It will guide you to run normally without

On the other hand, under the structure of the negative / electric conversion element 100 of the present invention, the diaphragm 102 is suspended in the air based on the back chamber BC while maintaining a relatively large area compared to its rigidity. Due to the formation of a structure, a very sensitive reaction to the surface force variable is inevitably generated, and as a result, if a humid environment is created during the manufacturing / use of the negative / pre conversion element 100, or the negative / pre conversion element If a severe environment such as an overcurrent is generated during the operation of the 100, it may fail to maintain its own original position and cause serious defects to stick to the cover plate 105 side.

In such a sensitive situation, as shown in FIG. 2, in the present invention, an adhesive barrier dimple having a structure protruding from the cover plate 105 side to the diaphragm 102 side around the acoustic hole 106 of the cover plate 103 ( 107 (Dimples) to take further measures (for reference, as will be described later, under the framework of the present invention, the adhesive blocking dimple 107 is to form the cover plate 105, without a separate self-forming procedure) In the course of the electroplating process for this, it is effectively subjected to the procedure formed simultaneously with the cover plate 105).

Of course, in the situation where the adhesive blocking dimples 107 are formed around the acoustic hole 106 of the cover plate 105 to take the structure protruding from the cover plate 105 side to the diaphragm 102 side, the sound / electric conversion A humid environment is created due to the manufacture / use of the device 100, or an overcurrent generating environment is created due to the operation of the negative / electro-electric conversion device 100, and thus, the diaphragm 102 has the cover plate 105. Even if it is to be adhered to the side, the diaphragm 102 is forced to be subjected to strong hindrance by the interference of the sticking blocking dimples 107 protruding and formed toward it, and eventually, under the tacking phenomenon according to the present invention, the producer On the side, due to the adhesion of the vibration plate 102 and the cover plate 105, the variable electrode 15 formed on the vibration plate 12 is in contact with the cover plate 13 serving as a fixed electrode, fire Various problems such as the occurrence of necessary electrical shorts> can be easily avoided, thereby effectively enjoying the advantage that the sound / pre conversion ability of the sound / pre conversion element 100 is greatly improved.

In this case, as shown in FIG. 2, in the present invention, measures for additionally forming a plurality of contact preventing holes 103a on the variable electrode 103 corresponding to the adhesion blocking dimple 107 are separately taken.

Of course, under such a situation that the contact preventing hole 103a is additionally formed, even if a phase for preventing adhesion of the diaphragm 102 is formed on the adhesive blocking dimple 107 side, without unnecessary electrical contact with the variable electrode 103, Located on the contact preventing hole (103a), it is possible to perform the above-mentioned adhesion phenomenon blocking function normally, after all, the manufacturer side to avoid damage due to unnecessary electrical contact of the adhesive blocking dimple 107 and the variable electrode 103 You can easily avoid it.

Hereinafter, a sequential manufacturing method of the sound / electric conversion element 100 according to the present invention having the above-described configuration will be described in detail.

First, as shown in FIG. 3A, in the present invention, a series of LPCVD processes, PECVD processes, and the like are performed using the front and rear surfaces of the substrate 101 as targets, for example, silicon nitride on the front and rear surfaces of the substrate 101. A procedure of forming the diaphragm 102 and the substrate buffer layer 102a having a material of (eg, Si ₃ N ₄ ) to a thickness of 900 μs to 1100 μs is performed.

Subsequently, as shown in FIG. 3B, in the present invention, a series of sputtering deposition processes are performed on the diaphragm 102 formed on the front surface of the substrate 101 to have a Cr / Au material on the diaphragm 102. The variable electrode raw material layer 103b is formed to have a thickness of 400 kPa to 600 kPa.

Next, as shown in FIG. 3C, in the present invention, a series of patterning processes, such as a photolithography process, are performed on the variable electrode material layer 103b formed on the diaphragm 102 to target the diaphragm 102. A variable electrode 103, an electrode rod 104 electrically connected to the variable electrode 103, and a series of contact preventing holes 103a disposed between the variable electrodes 103 are formed on the upper portion of the variable electrode 103. It will proceed to the procedure (see the above description for the detailed function of the contact preventing hole 103a).

In this case, the electrode rod 104 forms an electrical connection with the electrode pad 109 to be formed later, and serves to electrically connect the variable electrode 103 to the aforementioned signal processing chip (FIG. 2).

In this manner, when components such as the diaphragm 102, the variable electrode 103, the electrode rod 104, and the contact preventing hole 103a are completed on the front surface of the substrate 101, as shown in FIG. 3D. In the present invention, a series of dry etching processes (for example, RIE process) are performed on the substrate buffer layer 102a formed on the rear surface of the substrate 101 to remove some of the substrate buffer layer 102a, and then the remaining substrate buffer layer ( A series of Deep Reactive Ion Etching (Deep-RIE) processes are performed using the mask 102a as a mask, and a process of first etching and forming the back chamber BC is performed on the rear surface of the substrate 101. Of course, in this case, the etching process of the substrate buffer layer 102a described above may be simultaneously performed with deep reactive ion etching (Deep-RIE).

According to this procedure, when the back chamber BC is first etched and formed on the rear surface of the substrate 101, as shown in FIG. 3E, in the present invention, the diaphragm 102, the variable electrode 103, and the electrode rod ( A series of PECVD processes are performed on the entire surface of the substrate 101 including the 104 and the contact preventing hole 103a to target the variable electrode 103, the electrode rod 104, and the contact preventing hole 103a. For example, a procedure of forming an insulating source layer 108a having a SiO ₂ material to a thickness of about 0.9 μm to about 1.1 μm is performed on the diaphragm 102 including the same.

In the present invention, as shown in Figure 3f, through a series of patterning process, such as a photolithography process, the <insulation area to be formed of the cover plate 105> and <electrode rod contact hole 108b> exposed to expose The source layer 108 is selectively patterned so that the parasitic capacitance is formed on the upper part of the diaphragm 102 except for the &quot; floating region on the diaphragm 102 side where the variable electrode 103 is formed &quot; The parasitic capacitance reducing insulator layer 108 may be further formed to induce generation reduction (see the above description for the detailed function of the parasitic capacitance reducing insulator layer 108).

Next, in the present invention, as shown in FIG. 3G, the parasitic capacitance reducing insulator layer 108, the diaphragm 102, the variable electrode 103, the electrode rod 104, the contact preventing hole 103a, etc. A series of layer coating processes are performed on the entire surface of the substrate 101 including the polymer to form a polymer on the variable electrode 103, the diaphragm 102, and the parasitic capacitance reducing insulator layer 108. A process of forming a sacrificial layer raw material film 120a made of a series of materials, for example, photoresist, paraline, and phosphosilicate glass (PSG), has a thickness of about 2.2 μm to 2.8 μm. Done.

Next, in the present invention, the sacrificial layer raw material film 120a is soft baked at a temperature of 90 ° C. to 100 ° C. for about 85 seconds to 95 seconds, and then a series of patterning processes such as a photolithography process are performed. As shown in FIG. 3H, a portion of the sacrificial layer raw material film 120a is selectively removed, and through this, a photoresist on the side of the vibration plate 102 side support region on which the variable electrode 103 is formed, In addition to the procedure of forming / defining a sacrificial film 120 made of a polymer-based material such as paraline (Pralyne) and PhosphoSilicate Glass (PSG), the variable electrode 103 is formed on the sacrificial film 120. The procedure of forming / defining the anti-sticking dimple predetermined region 120b corresponding to the contact preventing hole 103 is performed. In this case, the aforementioned <adhesive blocking dimple scheduled region 120b> may naturally undergo a process of being simultaneously formed with the sacrificial film 120 only by simple adjustment of the exposure amount during the aforementioned patterning process.

In this way, when the sacrificial film 120, the anti-stick dimple planned area 120b, and the like are formed / defined, in the present invention, the sacrificial film 120, the anti-stick dimple planned area 120b, etc. are subjected to a series of steps. The hard bake process (Hard bake process) of the subsequent progress for about 25 minutes to 35 minutes at a temperature of 110 ℃ ~ 120 ℃, through which, the formation process of the sacrificial film 120 is completed.

Of course, in the above-described sacrificial film 120 formation procedure, the reason why all the process temperatures can be maintained at a low temperature (for example, room temperature to about 120 ° C.) is due to photoresist constituting the material of the sacrificial film 120. This is because Paraline (Palyne) and PhosphoSilicate Glass (PSG) have <features that are burned or denatured at low temperatures (for example, room temperature to about 120 ° C.) and are easily formed / removed. Under the procedural situation of the low temperature condition, the signal processing chip previously disposed on the circuit board can easily avoid damage due to thermal shock.

Through the above-described procedure, when the sacrificial film 120, the adhesive blocking dimple scheduled region 120b, and the like are formed on the upper side of the vibration plate 102 side support region on which the variable electrode 103 is formed, the present invention is shown in FIG. As shown in the figure, a series of sputtering processes are performed on the parasitic capacitance reducing induction insulating layer 108, the sacrificial layer 120, and the anti-sticking dimple scheduled region 120b formed on the entire surface of the substrate 101, respectively. The seed layer 109a having a Cr / Au material on the front surface of the components is formed to have a thickness of 1200 Å to 1500 Å. In this case, the seed layer 109a serves as a path through which charge moves during the progress of the <electroplating process for forming the cover plate 105> to be described later.

Subsequently, as shown in FIG. 3J, the seed layer 109a is sequentially subjected to a series of film coating processes, photolithography processes, and the like, and the acoustic hole 106 is disposed on the seed layer 109a. The procedure of forming the pattern mask 200 for defining the adhesive blocking dimple 107 and the cover plate 105 is performed. In this case, the pattern mask 200 has a photoresist material, for example.

In this way, when the pattern mask 200 for defining the acoustic hole 106, the adhesion blocking dimple 107, and the cover plate 105 is formed on the seed layer 109a, the present invention is illustrated in FIG. 3K. As described above, the electroplating process based on the seed layer 109a, for example, the nickel electroplating process, using the pattern mask 200 as a plating blocker, has a thickness of about 2.3 μm to 2.7 μm. Proceeding to a thickness, a process of forming a cover plate 105 made of nickel, which includes the acoustic hole 106 and the adhesive blocking dimple 107, surrounding the sacrificial layer 120 with its base matrix, is performed.

At this time, as described above, since the <adhesive blocking dimple predetermined region 120b corresponding to the contact preventing hole 103a of the variable electrode 103 is formed in advance, the adhesive blocking dimple 107 is effectively subjected to a process simultaneously formed with the cover plate 105 during the electroplating process for forming the cover plate 105, without a separate self-forming procedure.

Of course, as mentioned above, since the electroplating process can proceed at low temperatures (eg, room temperature to about 100 ° C.), under the implementation environment of the present invention, the signal processing chip previously disposed on the circuit board Silver can easily avoid damage due to thermal shock.

On the other hand, through the above-described procedure, while having the acoustic hole 106 and the adhesion blocking dimple 107, the cover plate 105 for wrapping the sacrificial layer 120 in its base matrix is completed, in the present invention, As illustrated in FIG. 3L, a series of exposure processes are performed to remove all of the pattern masks 200, thereby exposing the cover plate 105 and the seed layer 109a.

Subsequently, in the present invention, as shown in FIG. 3M, a series of film coating processes, photolithography processes, and the like are sequentially performed on the exposed cover plate 105 and the seed layer 109a, thereby covering the cover plate 105. And a pattern mask 201 for selectively patterning the seed layer 109a on the seed layer 109a. Also in this case, the pattern mask 201 has a photoresist material, for example.

In this manner, when the pattern mask 201 for selectively patterning the seed layer 109a is formed on the cover plate 105 and the seed layer 109a, as shown in FIG. 3N in the present invention, The pattern mask 201 is used as an etching mask, and a series of patterning processes are performed to remove a part of the seed layer 109a, thereby allowing the acoustic hole 106 belonging to the cover plate 105 to be removed. In addition to the opening, a procedure of selectively defining an electrode pad 109 forming an electrical connection with the electrode rod 104 is performed. In this case, as described above, the electrode pad 109 forms an electrical connection relationship with the electrode rod 104 forming an electrical connection relationship with the variable electrode 103, and describes the variable electrode 103 in detail. It is electrically connected to one signal processing chip (see FIG. 2).

As described above, in the present invention, since the electrode pads 109 are manufactured in a batch using the seed layer 109a, in the implementation environment of the present invention, the producer side may have various types of time / times that may occur when the electrode pads 109 are separately manufactured. Cost problems can be easily escaped.

Meanwhile, when the acoustic hole 106 belonging to the cover plate 105 is opened and the electrode pad 109 is selectively defined through the above-described procedure, in the present invention, as shown in FIG. Similarly, the back chamber BC targets the rear surface of the first defined substrate 101, and further advances a series of anisotropic wet etching processes (in this case, KOH may be used as an etchant, for example). A process of final etching and forming the back chamber BC of the completed shape defining the structure supporting the 102 and the variable electrode 103 is performed. In this case, the pattern mask 201 formed on the front surface of the substrate 101 acts as a series of protection bodies for protecting the electrode pad 109.

As mentioned above, in the conventional case, since a series of anisotropic etching processes using an etchant such as KOH was performed once without any action, the back chamber was formed, so that the overall profile of the back chamber is the silicon forming the substrate. According to the direction of the determination of, inevitably suffered the problem of inclining inward at a certain angle, after all, the overall size (scale) of the back chamber and the effective vibration area of the diaphragm formed thereon is due to the influence of It was inevitably reduced by the degree of inclination.

However, as described above, in the present invention, a series of deep reactive ion etching (Deep-RIE) processes are preliminarily performed, and the back chamber BC as shown by the dotted line in FIG. After the formation, the back chamber BC is further subjected to a series of anisotropic wet etching processes targeting the rear surface of the substrate 101 defined first to etch and form the completed back chamber BC. Therefore, the finally confirmed back chamber BC naturally additionally undergoes an <etching process in the dual crystallization direction indicated by an arrow in FIG. 3O, so that it is possible to actually expand its scale to the maximum size.

Of course, under the implementation environment of the present invention, when the size of the back chamber BC is substantially expanded to the maximum size, the effective vibration area of the vibration plate 102 formed in the space thereon is also greatly expanded in proportion thereto. As a result, the back chamber BC can normally perform the < role as sound tube &quot;, < role of maximizing the effective vibration area of the vibration plate 102 &quot;

On the other hand, through the above-described procedure, when the completed back chamber BC, which defines a structure for supporting the diaphragm 120 and the variable electrode 103 is completed etching and forming, as shown in FIG. In the same manner, a series of dry ashing processes are performed to remove the pattern mask 201 and the sacrificial layer 120 serving as a base matrix of the cover plate 105. (Of course, such a dry ashing process provides an excellent effect of preventing adhesion failure of the diaphragm 102 in advance as compared to a conventional wet etching process).

Of course, under such a dry ashing process, the sacrificial layer 120 disposed under the cover plate 105 is quickly removed while exiting through the sound hole 106 on the cover plate 105 side. As a result, a series of air gaps AG may be stably defined in the cover plate 105 occupied by the sacrificial layer 120.

At this time, since the acoustic hole 106 formed in the cover plate 105 acts as a series of passages through which the sacrificial layer 120 exits and is removed as described above, the overall occupying area of the acoustic hole 106 (that is, The area occupying the upper portion of the cover plate 105 serves as an important factor in the removal procedure of the sacrificial layer 120.

Of course, if the occupied area of the acoustic hole 106 is large, the sacrificial layer 120 may be advantageously removed, but in this case, another problem may occur in which the overall sensitivity of the sound / electric conversion element 100 is lowered. It may be.

In consideration of this variously, in the present invention, the overall occupation area of the acoustic hole 106 (that is, the area occupying the upper portion of the cover plate 105) is adjusted to about 25% to 60% of the area occupied by the variable electrode 103. As a result, the acoustic hole 106 is guided so that the acoustic hole 106 can appropriately contribute to the removal procedure of the sacrificial layer 120 without adversely affecting the sensitivity of the sound / electric conversion element 100.

On the other hand, as shown in Figure 4, in another embodiment of the present invention, the parasitic capacitance in the lower portion of the diaphragm 102 except for the support region (that is, the back chamber BC forming region), not the upper portion of the diaphragm 102 parasitic capacitance induced decrease the insulating layer 108 for deriving the amount of reduction, for example, it is taken to add an additional measure of forming the SiO ₂ layer in advance.

Of course, even under such a disposition of the parasitic capacitance-inducing insulating layer 108, for example, SiO ₂ layer, the insulating thickness between the cover plate 105 and the substrate 101 is <only the vibration plate 102 is formed alone Compared to the case, the parasitic capacitance generated at the portion A where the cover plate 105 and the substrate 101 are in contact with each other can be greatly reduced as compared with the related art.

As a matter of course, even under such a different implementation environment of the present invention, the production side can freely thin the thickness of the diaphragm 102, and the parasitic capacitance can be greatly improved. By utilizing the combination of the reduction induction insulating layer 108 and the diaphragm 102, the insulation thickness between the cover plate 105 and the substrate 101 can be stably maintained, and thus, the negative / electro-electric conversion element 100 It is possible to naturally maximize the overall sound / pre conversion quality of the).

For this structure, in the present invention, before the preceding diaphragm 102 is formed, a series of PECVD processes are performed in advance on the front surface of the substrate 101, so that, for example, SiO is formed on the substrate 101. _After forming an insulating source layer having a material of ₂ to about 0.9㎛ ~ 1.1㎛ thickness, through a series of patterning process such as a photolithography process, to proceed to pre-form the parasitic capacitance reduction insulated layer 108 (These procedures can be fully understood with reference to the above description, and for convenience, detailed drawings thereof will be omitted).

On the other hand, as shown in Figure 5, in another embodiment of the present invention locally increases the self-resistance of the substrate 101 in the substrate 101 corresponding to the cover plate 105, thereby reducing the amount of parasitic capacitance generated Further measures to further implant and form the ion doped layer 130 to induce the.

Of course, under such an additional formation and placement of the ion doped layer 130, the self-resistance of the substrate 101 in the region can be greatly increased, and as a result, the cover plate 105 and the substrate 101 mutually The amount of parasitic dose generated at the contacted area A can be greatly reduced as compared with the prior art.

As a matter of course, even under such an implementation environment of the present invention, the producer side can freely thin the thickness of the diaphragm 102 to significantly improve the function as the vibrating body imparted to the vibrating plate 102, while also providing an ion doping layer. By utilizing the 130, it is possible to stably manage the generation amount of the parasitic capacitance, and eventually, it is possible to naturally maximize the overall sound / pre conversion quality of the sound / pre conversion element 100.

For this structure, in the present invention, a series of ion implantation processes are performed in advance on the front surface of the substrate 101 before the diaphragm 102 is formed so that the cover plate 105 and the substrate 101 can be interconnected. A procedure of preforming the ion doped layer 130 is performed on the site where contact is expected.

Of course, under each of the above-described embodiments, in the present invention, the &quot; measurement for changing the sacrificial layer 120, which is the base matrix of the cover plate 105, to a polymer-based material that is easy to generate / remove at low temperature > A procedure for changing the formation procedure of the cover plate 105 to an electroplating procedure capable of proceeding at a low temperature>, &lt; adhesion to block adhesion of the diaphragm 102 and the cover plate 105 to a part of the cover plate 105 Flexible installation of blocking dimples (107: Dimple)>, <action of forming back chamber (BC) through deep process such as Deep Reactive Ion Etching (Deep-RIE) and anisotropic etching> Therefore, on the producer side, the one-step manufacturing process of the negative / electric conversion element 100 and the signal processing chip, the problem occurrence blocking caused by the adhesion of the cover plate 105 and the diaphragm 102, and the back chamber BC To maximize the scale naturally It becomes possible.

The present invention described above exhibits an overall useful effect in various types of electronic / electrical devices requiring the sound / electric conversion element 100.

And, in the foregoing, specific embodiments of the present invention have been described and illustrated, but it is obvious that the present invention may be variously modified and implemented by those skilled in the art. Such modified embodiments should not be understood individually from the technical spirit or point of view of the present invention and such modified embodiments should fall within the scope of the appended claims of the present invention.

1 is an exemplary view showing a sound / electric conversion element according to the prior art.

2 is an exemplary view showing a sound / electric conversion element according to the present invention.

3a to 3p are process flow charts sequentially showing a method of manufacturing a negative / electric conversion element according to the present invention.

4 and 5 are exemplary diagrams showing a sound / electric conversion element according to another embodiment of the present invention.

Claims (14)

A substrate on which a back chamber is defined; A diaphragm formed on the substrate such that the back chamber is covered; A variable electrode formed on a suspending area of the diaphragm corresponding to the back chamber; Defining a sound hole and an air gap, and including a cover plate formed on the diaphragm so that the variable electrode is covered and serving as a fixed electrode corresponding to the variable electrode, The cover plate is a negative / electro-electric conversion element, characterized in that formed by an electroplating (Electroplating process) using a polymer-based sacrificial layer (Sacrificial layer). The method of claim 1, wherein the insulation layer between the cover plate and the substrate is increased on the upper part of the diaphragm except for the support area, so that a parasitic capacitance reducing insulator layer is formed to induce a reduction in the amount of parasitic capacitance. Negative / electric conversion element. A substrate on which a back chamber is defined; A diaphragm formed on the substrate such that the back chamber is covered; A variable electrode formed on a suspending area of the diaphragm corresponding to the back chamber; Defining a sound hole and an air gap, and including a cover plate formed on the diaphragm so that the variable electrode is covered and serving as a fixed electrode corresponding to the variable electrode, A parasitic capacitance reducing insulator layer is formed on the lower portion of the diaphragm except for the support area to increase the insulation thickness between the cover plate and the substrate, thereby inducing a decrease in parasitic capacitance, and the cover plate is made of a polymer-based sacrificial layer ( A negative / electric conversion element formed by an electroplating process using a sacrificial layer. A substrate on which a back chamber is defined; A diaphragm formed on the substrate such that the back chamber is covered; A variable electrode formed on a suspending area of the diaphragm corresponding to the back chamber; Defining a sound hole and an air gap, and including a cover plate formed on the diaphragm so that the variable electrode is covered and serving as a fixed electrode corresponding to the variable electrode, An ion doping layer is formed in the substrate corresponding to the cover plate to locally increase the self-resistance of the substrate to induce a decrease in the amount of parasitic capacitance, and the cover plate forms a sacrificial layer of a polymer series. A negative / electric conversion element, characterized in that formed by the electroplating process (Utilization). The method of claim 1, wherein the sacrificial layer of the polymer series is a photoresist sacrificial layer, a paraline sacrificial layer, a PSG sacrificial layer (PhosphoSilicate). A sound / electric conversion element, characterized in that any one of the glass sacrificial layer. According to any one of claims 1, 3 or 4, the adhesive blocking dimples for preventing the diaphragm from sticking to the cover plate side around the sound hole of the cover plate. A negative / electric conversion element, characterized in that further formed. The negative / electric conversion element according to claim 6, wherein a contact preventing hole is further formed on the variable electrode corresponding to the adhesive blocking dimple to prevent electrical contact between the adhesive blocking dimple and the variable electrode. 5. The method of claim 1, 3 or 4, wherein the back chamber is defined through the dual progression of a Deep Reactive Ion Etching (Deep-RIE) process and an anisotropic wet etch process, the scale being A negative / electric conversion element, characterized in that it is substantially extended. The sacrificial hole according to any one of claims 1, 3, and 4, wherein the acoustic hole has an occupying area corresponding to 25% to 60% of an area occupied by the variable electrode on the cover plate. A negative / electric conversion element, which acts as a passage for removing layers. Forming a diaphragm on the front surface of the substrate; Forming a variable electrode on the diaphragm; Defining and forming a back chamber on a rear surface of the substrate; Forming a sacrificial layer of a polymer series on a region to be formed of a cover plate of the diaphragm; Forming a seed layer on the diaphragm including the sacrificial layer; Forming a pattern mask on the seed layer to define an acoustic hole, an adhesive barrier dimple and a cover plate; Using the pattern mask as a plating blocker, performing an electroplating process based on the seed layer to form a cover plate surrounding the sacrificial layer while having the acoustic hole and the adhesive blocking dimple; Removing the pattern mask and then selectively removing the seed layer to open the acoustic hole, and through the acoustic hole to remove the sacrificial layer to define an air gap inside the cover plate. Method of manufacturing a sound / electric conversion element comprising a. 12. The negative / electric conversion element according to claim 10, further comprising the step of further forming a parasitic capacitance reducing insulator layer to induce a reduction in the amount of parasitic capacitance generated above the diaphragm except for the back chamber forming region. Manufacturing method. The method of claim 10, further comprising preforming a parasitic capacitance reducing insulator layer for inducing a reduction in the amount of parasitic capacitance prior to the formation of the diaphragm. The method of claim 10, further comprising pre-injecting and forming an ion doped layer for inducing a reduction in the amount of parasitic capacitance in the substrate corresponding to the cover plate. The method of claim 10, wherein the defining and forming the back chamber on the rear surface of the substrate comprises performing a deep reactive ion etching (Deep-RIE) process on the rear surface of the substrate to first etch and form the back chamber. Wow; And further performing an anisotropic wet etching process to support the diaphragm and the variable electrode on the rear surface of the substrate having the back chamber defined first, and finally etching and forming the completed back chamber. A method of manufacturing a negative / electric conversion element, characterized by the above-mentioned.

Images