JP2004077404A - Method of manufacturing semiconductor gas rate sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method by which a semiconductor gas rate sensor which can maintain good airtightness, does not allow the protrusion of an adhesive, and is high in productivity and in which chips can be bonded accurately to each other. <P>SOLUTION: This method of manufacturing the semiconductor gas rate sensor includes a transparent film fitting step (ST13) of fitting a transparent film provided with transmitting spheres which transmit the adhesive to the joint surfaces of Si wafers, a step (ST14) of applying the adhesive to the joint surfaces of the Si wafers in forms following the transmitting spheres by transmitting the adhesive from the upside of the transmitting film, and a step (ST15) of bonding the joint surfaces of first and second Si wafers 23 and 24 to each other by aligning the first alignment mark 28 of the first wafer 23 and the second alignment mark of the second wafer 24 with prescribed positions by reading the alignment marks 28 and 29 by transmitting infrared rays through the marks 28 and 29. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for manufacturing a semiconductor gas rate sensor, and more particularly to a method for manufacturing a semiconductor gas rate sensor using bonding between Si wafers in a process for manufacturing a micro gas rate sensor as a micromachining element.
[0002]
[Prior art]
As a method for bonding the upper and lower semiconductor substrates, an anodic bonding between glass and Si and a bonding method using low melting point glass as disclosed in Japanese Patent Application Laid-Open No. 3-29858 are known. However, in these joining methods, it is very difficult to maintain airtightness when there are irregularities, and there is a problem that the adhesive sticks out of a predetermined position where the adhesive is applied.
[0003]
Japanese Patent Laid-Open Publication No. Hei 6-334315 discloses a method of forming such a semiconductor member by bonding upper and lower semiconductor substrates at predetermined positions to solve such a problem. The method uses a film-like adhesive consisting of a reinforcing material and an adhesive layer as an adhesive, and cuts and cuts the film-like adhesive, or presses the film-like adhesive against the bonding surface of a chip component or a circuit board as it is. The adhesive layer is heated to a temperature at which the adhesive layer softens but does not cure, and the adhesive layer is transferred to the bonding surface, and the bonding surface of the chip component or the circuit board to be bonded is aligned with the bonding surface. Is carried out by curing.
[0004]
That is, the adhesive formed in a predetermined shape is transferred to one chip member by so-called thermal transfer, and after bonding the other chip member to the chip member, heat is applied at a higher temperature than that of the thermal transfer to thermally cure the adhesive. And join them together.
[0005]
[Problems to be solved by the invention]
However, in the joining method disclosed in Japanese Patent Application Laid-Open No. 6-334315, different temperature applying steps for heat transfer and adhesive curing are required, and an operation of removing the adhesive sheet between these heating steps is required. Therefore, there is a problem that the heating operation cannot be performed continuously and the manufacturing process becomes complicated. In addition, in the thermal transfer, a predetermined temperature must be strictly controlled so that the adhesive is not hardened, so that the manufacturing process is complicated. In addition, there is a problem that it can be performed only by a single chip member and is disadvantageous in terms of productivity. In addition, although the publication describes a method of bonding chip members, that is, a bonding method, it discloses any technique for correctly recognizing the positions of the chip members and bonding the chip members at desired portions. Did not. Further, in order to bond the chip members, it is necessary to bond the chips with high accuracy. If the bonding cannot be performed with the desired accuracy, a problem arises in that a desired gas flow cannot be obtained due to a poor sealing property as a gas passage or a displacement of the gas passage, and a reduction in sensing efficiency due to a displacement of the heat sensor. There is.
[0006]
An object of the present invention is to solve the above-mentioned problems, to maintain good airtightness, to prevent the adhesive from protruding, and to bond chips with high accuracy, and to further improve the productivity of the semiconductor. A method of manufacturing a gas rate sensor is provided.
[0007]
Means and action for solving the problem
A method for manufacturing a semiconductor gas rate sensor according to the present invention is configured as follows to achieve the above object.
[0008]
According to a first method for manufacturing a semiconductor gas rate sensor (corresponding to claim 1), a heat wire bridge having a detection unit formed of a pair of heat wires is provided in a gas passage, and an angular velocity is determined from deviation of a gas flow hitting the heat wire. In a method of manufacturing a semiconductor gas rate sensor for detecting, a first alignment mark forming step of forming a plurality of first alignment marks on a bonding surface of a first Si wafer, and a plurality of first alignment marks forming a plurality of first alignment marks on a bonding surface of a second Si wafer. A second alignment mark forming step of forming a second alignment mark, a function part forming step of forming a half-groove serving as a gas passage and a heat wire bridge having a detection part formed of a pair of heat wires on the first Si wafer; A half-groove forming step of forming a half-groove serving as a gas passage in the second Si wafer; A permeable membrane addressing step for addressing a permeable membrane provided with a permeable area for allowing the adhesive to pass through the joint surface, and transmitting the adhesive from above the permeable membrane to form the first Si in a shape according to the permeable area. Applying an adhesive to the bonding surface of the wafer or the second Si wafer, and reading the first alignment mark of the first Si wafer and the second alignment mark of the second Si wafer by transmitting infrared rays And aligning the first alignment mark and the second alignment mark at predetermined positions, and bonding the first Si wafer bonding surface and the second Si wafer bonding surface together. Attached.
[0009]
According to the first method for manufacturing a semiconductor gas rate sensor, since bonding is not performed between chip components but in a wafer state during a process, bonding can be performed with high accuracy. Thus, the complexity of the manufacturing process can be avoided, and the productivity can be increased. In addition, since the alignment marks are read through infrared rays and read and the alignment of the Si wafer is performed, two Si wafers can be bonded accurately. Furthermore, an adhesive is applied from above the permeable film, a shape according to the transmission range is applied to one adhesive surface of the semiconductor substrate, and the other semiconductor substrate is attached and adhered thereto. If the agent is of a thermosetting type, since the adhesive can be immediately cured after the application of the adhesive, it is possible to avoid the complexity of the manufacturing process, which requires heating in multiple steps as in the conventional technology. be able to. In addition, even if the semiconductor substrate has a contact portion and the bonding surface has a more complicated shape, the bonding operation can be performed smoothly. Further, since a large number of semiconductor members can be smoothly bonded at one time, an extremely efficient bonding operation can be provided when a large number of semiconductor members are obtained from one semiconductor substrate.
[0010]
According to a second method for manufacturing a semiconductor gas rate sensor (corresponding to claim 2), in the above method, preferably, a (100) plane is used as a bonding surface between the first Si wafer and the second Si wafer. It is characterized by
[0011]
According to the second method for manufacturing a semiconductor gas rate sensor, since the bonding surface is the (100) plane, favorable anisotropic etching can be performed.
[0012]
According to a third method of manufacturing a semiconductor gas rate sensor (corresponding to claim 3), in the above method, preferably, the half groove serving as a gas passage of the first Si wafer and the first alignment mark are simultaneously wet-etched. It is characterized by forming.
[0013]
According to the third method for manufacturing a semiconductor gas rate sensor, since the etching process of the alignment mark and the gas passage is performed at once from the resist patterning, the positional relationship between the alignment and the gas passage is smaller than that in the case of bonding in a chip component state. Accuracy can be improved. In addition, the sensing performance can be improved as the accuracy of the shape of the gas passage and the position of the heat sensor are improved.
[0014]
In a fourth method of manufacturing a semiconductor gas rate sensor (corresponding to claim 4), in the above method, preferably, the half groove serving as a gas passage of the second Si wafer and the second alignment mark are simultaneously wet-etched. It is characterized by forming.
[0015]
According to a fifth method of manufacturing a semiconductor gas rate sensor (corresponding to claim 5), in the above method, preferably, a mask is provided on the (100) plane of the first Si wafer or the (100) plane of the second Si wafer. The method is characterized in that a pattern is placed and anisotropic wet etching is performed to form a contact portion along the <111> direction of the first Si wafer or the second Si wafer.
[0016]
According to the fifth method for manufacturing a semiconductor gas rate sensor, it is possible to control the depth direction by the shape of the mask pattern on the (100) plane. The depth of the alignment mark is as deep as 420 μm (micron), but the depth of the alignment mark can be suppressed to several tens of μm (micron). Can be.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.
[0018]
The configurations, shapes, sizes, and arrangements described in the embodiments are only schematically shown to the extent that the present invention can be understood and implemented, and the numerical values and the compositions (materials) of each configuration are only examples. Only. Therefore, the present invention is not limited to the embodiments described below, and can be modified in various forms without departing from the scope of the technical idea described in the claims.
[0019]
FIG. 1 is an exploded perspective view of a semiconductor member for a gas rate sensor manufactured using the method for manufacturing a semiconductor gas rate sensor according to the present invention. The semiconductor member 10 for a gas rate sensor includes a lower semiconductor substrate 11, an upper semiconductor substrate 12, and a heat wire bridge 15 having heat wires 13 and 14, which are functional units, as constituent members. Contact portions 16 and 17 serving as gas passages are formed in the substrate 12. The lower semiconductor substrate 11 and the upper semiconductor substrate 12 are made of a semiconductor such as Si. The heat wires 13 and 14 are detection units, and the heat wire bridge 15 is for fixing the detection unit to the gas passage.
[0020]
The gas rate sensor semiconductor member 10 is used in a state where the lower semiconductor substrate 11 and the upper semiconductor substrate 12 are joined. FIG. 2 is a schematic diagram illustrating a configuration of the gas rate sensor. The gas rate sensor 18 includes a sensor chip 19 and a piezo pump 20. The sensor chip 19 includes the semiconductor member 10 for a gas rate sensor and the gas introduction unit 21. The piezo pump 20 supplies a gas to the gas introduction unit 21 to create a gas flow in the sensor chip 19 as indicated by an arrow.
[0021]
In the gas rate sensor 18, a gas is introduced from an inlet 22 of a gas passage by a piezo pump 20, and the gas flows through the gas passage and is blown to the heat wires 13 and 14. The left and right heat wires 13 and 14 whose temperature is increased by the current at that time are cooled by the blown gas. These heat wires form a bridge circuit (not shown), and when the flow rates of the gas blown to the left and right heat wires 13 and 14 are equal, the temperatures of the two heat wires 13 and 14 are equal, and as a result, The output voltage at the bridge circuit becomes zero. However, when the gas rate sensor has an angular velocity, Coriolis force acts on the gas flow, and the gas flow drifts. As a result, a difference occurs in the speed of the gas flow that blows the heat wires 13 and 14 on the left and right sides of the gas, so that the electric resistance of the heat wires differs between the left and right, the balance of the bridge circuit is broken, and the output voltage is detected. You. As a result, the angular velocity can be measured.
[0022]
FIG. 3 is a flowchart showing a manufacturing process in the first embodiment of the method for manufacturing a semiconductor gas rate sensor according to the present invention. In this method of manufacturing a semiconductor gas rate sensor, a step (ST10) of forming an alignment mark on the first Si wafer and the second Si wafer, a heat wire bridge having heat wires on the first Si wafer, a gas passage, A functional portion forming step (ST11) for forming a semi-groove, a semi-groove forming step (ST12) for forming a semi-groove serving as a gas passage in a second Si wafer, and a first Si wafer or a second Si wafer. A step (ST13) of addressing a permeable membrane having a permeable area through which an adhesive is allowed to pass through the bonding surface, and transmitting the adhesive from above the permeable membrane to form a shape according to the permeable area. A step of applying an adhesive to the bonding surface of the first Si wafer or the second Si wafer (ST14), and bonding and bonding the bonding surface of the first Si wafer and the bonding surface of the second Si wafer. Extent and (ST15), the step of subdividing cut out Si wafer bonded body formed by these steps (ST16), the semiconductor element is fabricated for semiconductor gas rate sensor. By attaching a piezo pump or the like to the semiconductor member for the semiconductor gas rate sensor, a semiconductor gas rate sensor can be obtained.
[0023]
Next, each step will be described in detail. FIG. 4 is a flowchart showing a step (ST10) of forming an alignment mark on the first Si wafer and the second Si wafer. In this step, a resist coating step (ST20) of applying a resist to the first and second Si wafers for forming the alignment marks and a mask having an opening formed so as to expose the resist in the portion for forming the alignment marks are applied. A photolithography step of removing the resist by exposure (ST21) and a step of etching the first and second Si wafers (ST22).
[0024]
In the resist coating step ST20, a positive resist that becomes soluble by light is applied to a uniform thickness by a spin coater (not shown). FIG. 5 shows a cross section of the Si wafer at that time. The entire surface of the first Si wafer 23 and the second Si wafer 24 is in a state where a positive resist 25 is applied.
[0025]
Next, in a photolithography process (ST21), two types of masks (not shown) each having an opening formed so as to correspond to a plurality of alignment marks are coated with a resist 25 on a first Si wafer and a second Si wafer. The wafer is brought into close contact with each other, and is exposed to light having a wavelength at which the resist reacts by an exposure device. Thereafter, the first Si wafer and the second Si wafer are immersed in a solvent, whereby the exposed portions of the resist dissolve and the portions of the resist forming the alignment marks are removed. FIG. 6 shows a cross section of the first Si wafer and a cross section of the second Si wafer at that time. On the surface of the first Si wafer 23, a resist opening 26 is formed in a portion where a first alignment mark is formed, and in the surface of the second Si wafer 24, a resist opening is formed in a portion where a second alignment mark is formed. Opening 27 is formed.
[0026]
In the etching step (ST22), the first Si wafer and the second Si wafer are immersed in an etchant for a predetermined time, so that Si in the resist openings 26 and 27 is etched, and the first and second alignments are performed. A mark is formed. FIGS. 7A and 7B show cross sections of the first Si wafer and the second Si wafer at that time. A first alignment mark 28 is formed on the first Si wafer 23, and a second alignment mark 29 is formed on the second Si wafer 24. Thereafter, by removing the resist 25, a first Si wafer having the first alignment mark and a second Si wafer having the second alignment mark are obtained.
[0027]
FIGS. 8A and 8B show a first Si wafer having a first alignment mark and a second Si wafer having a second alignment mark manufactured in this manner. A first alignment mark 28 is formed on the first Si wafer 23, and a second alignment mark 29 is formed on the second Si wafer 24.
[0028]
FIG. 9 is a flowchart showing a step (ST11) of forming a heat wire bridge having heat wires and a half groove serving as a gas passage on the first Si wafer. This step includes an insulating film forming step (ST30) of forming an insulating film made of SiN on the first Si wafer and a metal resistance layer of forming a thin metal resistance layer by depositing a heat-sensitive resistor such as platinum on the insulating film. A thin film forming step (ST31) and a heat wire and electrode forming step (ST32) of forming a heat wire by patterning the metal resistive layer into a predetermined shape by etching, and similarly forming electrode portions on both sides thereof And a protection film forming step of forming a protection film made of SiN on the heat wire and the electrode (ST33), and a heat treatment step of performing a heat treatment for suppressing a temporal change of the thermal resistance characteristic of the heat wire itself (ST34). Etching the first Si wafer to form a half hole and a half groove, and remove the Si under the heat wire by etching. And consisting of an etching step (ST35) of forming the heat-wire bridge.
[0029]
In the insulating film forming step (ST30), SiN is deposited on the surface of the first Si wafer on which the alignment mark is formed by chemical vapor deposition (CVD) or sputtering. FIG. 10A shows a cross section of the first Si wafer 23 at that time. The entire surface of the first Si wafer is in a state where SiN 30 is deposited.
[0030]
Next, in the metal resistance layer thin film forming step (ST31), platinum or the like is deposited on the first Si wafer on which SiN is deposited by a deposition device (not shown). FIG. 10B shows a cross section of the Si wafer at that time. SiN 30 is deposited on the entire surface of the first Si wafer 23, and platinum 31 is deposited thereon.
[0031]
In the heat wire and electrode forming step (ST32), platinum 31 deposited on the surface of the first Si wafer is patterned into a predetermined shape and the platinum is etched. FIG. 10C shows a cross section of the Si wafer at that time. SiN 30 is deposited on the entire surface of the Si wafer, and patterned platinum 31 is deposited thereon.
[0032]
In the protective film forming step (ST33), SiN is deposited on the first Si wafer surface formed in the heat wire and electrode forming step (ST32) by chemical vapor deposition (CVD) or sputtering. FIG. 10D shows a cross section of the first Si wafer at that time. On the entire surface of the Si wafer, a SiN layer 30, a patterned platinum layer 31, and a SiN 32 layer are formed thereon.
[0033]
In the heat treatment step, the Si wafer is placed in an electric furnace and heated at about 700 ° C. for several tens of minutes. This suppresses a change with time in the heat-sensitive resistance characteristics of the heat wire itself.
[0034]
Next, in an etching step (ST35), a half hole and a half groove 33 as shown in FIG. 10E are formed, and a heat wire bridge 34 is formed.
[0035]
FIG. 11 shows the first Si wafer 23 having the functional unit manufactured as described above. On the first Si wafer 23, a contact portion 35 having an alignment mark 28 and a plurality of heat wire bridges 34 is formed, and the shape of each etched portion is shown in FIG. It comprises a contact portion 36 corresponding to the nozzle portion 36a for guiding the gas flow supplied from the piezo pump 20 to the detection portion, and a contact portion 37 on which a heat wire is placed.
[0036]
FIG. 12 is a flowchart showing a step (ST12) of forming a half groove in the second Si wafer 24. In this step, a resist application step (ST40) of applying a resist to a second Si wafer forming a half groove, and an opening was formed so as to expose a portion of the resist forming a half groove having a shape shown in the drawing. It comprises a photolithography step (ST41) of removing a resist by applying a mask and exposing the resist, and a step (ST42) of etching the second Si wafer.
[0037]
In the resist coating step ST20, a positive resist that becomes soluble by light is applied to a uniform thickness by a spin coater (not shown). FIG. 13A shows a cross section of the second Si wafer 24 at that time. The entire surface of the second Si wafer 24 is in a state where a positive resist 38 is applied.
[0038]
Next, in a photolithography step (ST41), a resist having a resist applied to a mask having an opening corresponding to a contact portion for forming a gas passage of a plurality of gas rate sensors is applied. The substrate is brought into close contact with the wafer 24, and is exposed to light having a wavelength at which the resist reacts by an exposure device (not shown). Then, by dipping the second Si wafer 24 in a solvent, the exposed portion of the resist melts and the portion of the resist forming the contact portion is removed. FIG. 13B shows a cross section of the second Si wafer at that time. On the surface of the second Si wafer 24, a resist opening 39 is formed at a portion where a contact portion is to be formed.
[0039]
In the etching step (ST42), the second Si wafer is immersed in an etchant for a predetermined time, so that Si in the resist opening 39 is etched to form a contact portion. FIG. 13C shows a cross section of the second Si wafer at that time. A contact portion 40 is formed on the second Si wafer 24. Thereafter, by removing the resist 38, the second Si wafer 24 having the contact portion 40 is obtained.
[0040]
FIG. 14A shows the second Si wafer 24 having the contact portions 40 and the alignment marks 29 manufactured in this manner. On the second Si wafer 24, an alignment mark 29 and a scribed portion 40 are formed, and the shape of each of the scribed portions 40 is shown in FIG. 14B and supplied from the piezo pump 20. It comprises a contact portion 41 and a contact portion 42 corresponding to the nozzle portion 41a for guiding the gas flow to be detected to the detection portion.
[0041]
Next, a permeable membrane addressing step (ST13) in which a permeable area in which the adhesive is allowed to pass through is provided on the bonding surface of the first Si wafer or the second Si wafer (ST13). A step of applying an adhesive to the bonding surface of the first Si wafer or the second Si wafer in a shape according to the transmission range by transmitting the agent (ST14); The first specific example up to the step (ST15) of bonding and bonding the bonding surfaces of the Si wafer will be described.
[0042]
FIG. 15 is a diagram showing a permeable membrane addressing step (ST13) for addressing a permeable membrane provided with a permeable area for allowing the adhesive to pass through the bonding surface of the first Si wafer or the second Si wafer. In this step (ST13), the adhesive transmitting device 43 is used. The adhesive transmitting device 43 includes a substrate fixing portion 44, an adhesive transmitting film frame 45, and a transmitting film 46. The substrate fixing section 44 is for fixing the first Si wafer or the second Si wafer to which the adhesive is applied, and the adhesive permeable film frame 45 is for fixing the permeable film 46. The adhesive permeable film frame 45 holds the permeable film 46 so that an appropriate tension is applied to the permeable film 46. Here, a case where an adhesive is applied to the second Si wafer will be described as an example.
[0043]
FIG. 16 shows a partially enlarged view of the permeable membrane. The permeable membrane 46 is composed of a woven fabric 47 made of a wire material such as stainless steel wire, silk, nylon, or Tetron fiber, and a resist 48. The woven fabric 47 has fine eyes, and there are a portion 49 closed with a resist and a portion 50 without a resist, and the closed portion 49 is accurately formed on the first Si wafer or the second Si wafer. It is a part corresponding to the touching part of. The adhesive will pass through portions without the resist 48. The portion 50 without the resist 48 is a transmission range through which the adhesive is transmitted.
[0044]
The substrate fixing portion 44 and the adhesive permeable film frame 45 sandwich the second Si wafer 24 between the substrate fixing portion 44 and the adhesive permeable film frame 45 can be accurately closed. A concave portion having the shape of the second Si wafer 24 is formed in the substrate fixing portion 44 so that the fixing position of the second Si wafer 24 is accurately aligned with and fixed to the transmission range of the transmission film 46. I have. FIG. 17 shows a cross section of the substrate fixing portion 44. There is a depression 51 having a depth such that the bonding surface of one Si wafer is slightly protruded and enters, and a hole 52 is formed below the depression 51, from which the bonded Si wafer is pushed to It is intended to be able to be taken out from the fixing portion 44.
[0045]
First, the second Si wafer 24 to be coated with an adhesive having a contact portion is set in the depression 51 of the substrate fixing portion 44 using the adhesive transmitting device 43. After that, the adhesive permeable film frame 45 is closed, and the permeable film 46 is directed to the second Si wafer 24.
[0046]
FIG. 18 is a diagram showing the adhesive application step (ST14). A paste adhesive 53 is applied to the permeable membrane 46. Thereafter, the adhesive 53 is spread by applying pressure with a spatula 54 or the like, so that the adhesive 53 penetrates through the resist-free eyes of the permeable film. As a result, the adhesive is reliably applied only to the periphery of the contact portion of the second Si wafer 24, and the adhesive is applied without interruption and in a uniform thickness.
[0047]
FIG. 19 shows a cross section of the Si wafer at this time. The adhesive layer 55 is accurately applied to the surface of the second Si wafer 24 other than the contact portion.
[0048]
Next, a step (ST15) of bonding the bonding surface of the first Si wafer and the bonding surface of the second Si wafer together will be described. In this step, an alignment device 56 as shown in FIGS. This device 56 has infrared lamps 57 and 58 that transmit the positions of the alignment marks on both the first Si wafer and the second Si wafer, and two infrared cameras 59 and 60 that detect infrared rays from these lamps. is there. Then, there are a lower stage 61 and an upper stage 62 made of glass for setting the second Si wafer 24 and the first Si wafer 23. As shown in FIG. 21, the lower stage 61 and the upper stage 62 have openings 63 and 64 at the center. A vacuum device 65 capable of evacuating is attached to a lower portion of the opening 63 of the lower stage 61. Above the opening 64 of the upper stage 62, a vacuum device 66 for vacuuming is attached. The upper stage 62 is attached to a movable shaft 67 that can move in the X and Y directions, and the upper stage 62 can rotate around the movable shaft 67. Images from the infrared cameras 59 and 60 can be observed on the display 68.
[0049]
Next, a procedure for bonding the first Si wafer and the second Si wafer using the alignment device 56 will be described with reference to FIG. The second Si wafer 24 is set on the lower stage 61. Then, the vacuum device 65 is operated to evacuate. Thereby, second Si wafer 24 is fixed to lower stage 61 (ST50). Next, the first Si wafer 23 is addressed to the lower side of the upper stage 62, and the vacuum device 66 is operated in that state. Thereby, first Si wafer 23 is fixed to upper stage 62 (ST51). In this state, the infrared lamps 57 and 58 are turned on, and the infrared cameras 59 and 60 are operated. At this time, the infrared light passes through the first Si wafer and the second Si wafer, and the images of the alignment marks at both ends of both Si wafers are displayed on the display 68 (ST52).
[0050]
FIGS. 23A, 23B and 23C show images of the alignment marks at that time. The stage is rotated and moved in the X and Y directions until the alignment mark 28 on the first Si wafer 23 is aligned with the alignment mark 29 on the second Si wafer as shown in FIG. ST53). 23 (c) is when the surfaces of the first Si wafer and the second Si wafer coincide with each other. At this time, the upper stage 62 is lowered, and the second Si wafer on the lower stage 61 is moved downward. Is bonded to the first Si wafer 23 of the upper stage 62 (ST54).
[0051]
FIG. 24 shows a cross-sectional view of a bonded body 69 of the first Si wafer and the second Si wafer after bonding. The first Si wafer 23 and the second Si wafer 24 are bonded, and the gas passage 70 is formed accurately.
[0052]
A plurality of semiconductor members for a gas rate sensor are completed by cutting out and subdividing the joined body 69 (ST16 in FIG. 3). At this time, by making a cut in advance in a portion to be cut into the first Si wafer or the second Si wafer, the semiconductor member is easily divided into one by the cleavage of the semiconductor, and the semiconductor member is subdivided. be able to.
[0053]
By using this method for manufacturing a semiconductor gas rate sensor, the gas tightness is maintained, the adhesive does not protrude, the number of members required for the process is small, and the productivity is high in the manufacturing process without complexity. Can be manufactured.
[0054]
Next, a permeable membrane addressing step (ST13) in which a permeable area in which the adhesive is allowed to pass through is provided on the bonding surface of the first Si wafer or the second Si wafer (ST13). A step of applying an adhesive to the bonding surface of the first Si wafer or the second Si wafer in a shape according to the transmission range by transmitting the agent (ST14); The second specific example up to the bonding surface alignment step (ST15) of aligning the bonding surfaces of the Si wafers will be described.
[0055]
In these steps, an alignment device 71 as shown in FIG. 25 is used. This device 71 has infrared lamps 72 and 73 that transmit the positions of the alignment marks on both the first Si wafer and the second Si wafer, and two infrared cameras 74 and 75 that detect infrared rays from these lamps. is there. Then, there are a lower stage 76 and an upper stage 77 made of glass for mounting the second Si wafer 24 and the first Si wafer 23. In addition to the lower stage 76 and the upper stage 77, there is a permeable membrane stage 78. As in the case shown in FIG. 21, the lower stage 76 and the upper stage 77 have openings in the center. A vacuum device capable of evacuating is attached to a lower portion of the opening of the lower stage 76. Above the opening of the upper stage 77, a vacuum device for vacuuming is attached. The upper stage 77 is attached to a movable shaft 79 that can move in the X and Y directions, and the upper stage 77 can rotate around the movable shaft 79 and can move up and down along the movable shaft. .
[0056]
The permeable membrane stage 78 includes an adhesive permeable membrane 80 and a permeable membrane 81. The adhesive permeable membrane frame 80 is for fixing the permeable membrane 81. The adhesive permeable membrane frame 80 holds the permeable membrane 81 so that an appropriate tension is applied to the permeable membrane 81. The transmission film 81 has the same structure as the transmission film 46 shown in FIG. 16 except that two alignment marks 82 and 83 are provided. The permeable membrane stage 78 is attached to a movable shaft 84 that can move in the X and Y directions, and the permeable membrane stage 78 can rotate about the movable shaft 84 and can move up and down along the movable shaft 84. It has become.
[0057]
The images from the infrared cameras 74 and 75 can be observed on the display 85.
[0058]
Next, a procedure for bonding the first Si wafer and the second Si wafer using the alignment device 71 will be described with reference to FIG. The second Si wafer 24 is set on the lower stage 76. Then, the vacuum device is operated to evacuate. Thereby, second Si wafer 24 is fixed to lower stage 76 (ST60).
[0059]
Next, the permeable membrane stage 78 is positioned above the lower stage 76, and in that state, the infrared lamps 72, 73 are turned on, and the infrared cameras 74, 75 are also operated. At this time, the infrared rays project the images of the alignment marks 82 and 83 at both ends of the transmission film 81 and the images of the two alignment marks on the second Si wafer 24 on the display (ST61). The permeable film stage 78 is moved and rotated in the XY directions until the alignment marks 82 and 83 of the permeable film 81 are aligned with the alignment marks of the second Si wafer 24 (ST62). The transmission film stage 78 is lowered while aligning the alignment marks 82 and 83 of the transmission film 81 with the alignment marks of the second Si wafer 24, and the transmission film is addressed to the second Si wafer 24 on the lower stage 76 (ST63). ).
[0060]
Next, in an adhesive application step (ST14), a paste-like adhesive is applied to the permeable membrane 81. Thereafter, the adhesive is spread by applying pressure with a spatula or the like, so that the adhesive permeates the resist-free eyes of the permeable film 81. As a result, the adhesive is reliably applied only to the periphery of the engraved portion of the second Si wafer 24, and the adhesive is applied to a uniform thickness without interruption (ST64). Thereafter, the permeable film stage 78 is raised, the permeable film 81 is separated from the second Si wafer 24, and the permeable film stage 78 is rotated (ST65).
[0061]
At this time, the adhesive layer 46 is accurately applied to the surface of the second Si wafer 24 other than the engraved portion, similarly to the cross section of the Si wafer shown in FIG.
[0062]
Next, the first Si wafer 23 is addressed to the lower side of the upper stage 77, and the vacuum device is operated in that state. Thereby, first Si wafer 23 is fixed to upper stage 77 (ST66). In this state, the infrared lamps 72 and 73 are turned on, and the infrared cameras 74 and 75 are operated. At this time, the infrared light passes through the first Si wafer and the second Si wafer, and the images of the alignment marks at both ends of both Si wafers are displayed on the display 85 (ST67).
[0063]
At this time, an image of an alignment mark similar to that shown in FIGS. 21 (a), (b) and (c) is displayed. The stage is rotated and moved in the X and Y directions until the alignment mark 28 of the first Si wafer 23 overlaps with the alignment mark 29 of the second Si wafer as shown in FIG. ST68). 21 (c) is when the surfaces of the first Si wafer and the second Si wafer coincide with each other. At this time, the upper stage 77 is lowered and the second stage on the lower stage 76 is moved. Is bonded to the first Si wafer 23 of the upper stage 77 (ST69).
[0064]
As a result, the first Si wafer 23 and the second Si wafer 24 are bonded to each other, as in the case shown in FIG.
[0065]
In the specific example 2, as in the specific example 1, the joined body is cut out and subdivided to complete a plurality of semiconductor members for a gas rate sensor. At this time, by making a cut in advance in a portion to be cut into the first Si wafer or the second Si wafer, the semiconductor member is easily divided into one by the cleavage of the semiconductor, and the semiconductor member is subdivided. be able to.
[0066]
By using this method for manufacturing a semiconductor gas rate sensor, the gas tightness is maintained, the adhesive does not protrude, the number of members required for the process is small, and the productivity is high in the manufacturing process without complexity. Can be manufactured.
[0067]
Next, a permeable membrane addressing step (ST13) in which a permeable area in which the adhesive is allowed to pass through is provided on the bonding surface of the first Si wafer or the second Si wafer (ST13). A step of applying an adhesive to the bonding surface of the first Si wafer or the second Si wafer in a shape according to the transmission range by transmitting the agent (ST14); The third specific example up to the bonding surface aligning step (ST15) of aligning the bonding surfaces of the Si wafer will be described.
[0068]
In the process of the third specific example, an alignment device 86 as shown in FIGS. 27 and 28 is used. The device 86 includes a stage slider 87, an infrared light source 88 that transmits the positions of alignment marks on both the first Si wafer and the second Si wafer, an infrared camera 89 for detecting infrared light from the light source 88, and a monitor. There are 90. The stage slider 87 is provided with a slider rail 91 for stage A, a slider rail 92 for stage B, and a slider rail 93 for stage C. The stage 97 moves by moving the knob 97 by a stage A95 having a wafer holder 94 for transmitting the infrared ray for setting the second Si wafer 24, a fixed claw 96 for fixing the first Si wafer, and a spring. There is a rotary frame 100 that can be rotated by a wafer holding claw 98 and a knob 99, a frame 102 that can be moved by an X-direction knob 101, and a stage C103 that has a knob 104 that moves in the Y direction of a stage C103. There is a permeable membrane stage B105 in addition to the stage A95 and the stage C103.
[0069]
The permeable membrane stage B105 includes an adhesive permeable membrane frame 106 and a permeable membrane 107. The adhesive permeable membrane frame 106 is for fixing the permeable membrane 107. The adhesive permeable film frame 106 holds the permeable film 107 so that an appropriate tension is applied to the permeable film 107. The transmission film 107 has the same structure as the transmission film 46 shown in FIG. 16 except that two alignment marks 108 and 109 are provided. The stage B105 has a rotating frame 111 that can be rotated by a knob 110, a frame 113 that can be moved by an X-direction knob 112, and a knob 114 that moves the stage B105 in the Y direction.
[0070]
The image from the infrared camera 89 can be observed on the monitor 90.
[0071]
Next, a procedure for bonding the first Si wafer and the second Si wafer using the alignment device 86 will be described with reference to FIGS. The second Si wafer 24 is set on the stage A95 and fixed (ST70 and FIG. 29A).
[0072]
Next, the stage B 105 is positioned above the stage A 95 on the slider 87 (FIG. 29B), and in this state, the infrared light source 88 is turned on and the infrared camera 89 is also operated. At this time, the infrared rays project the images of the alignment marks 108 and 109 at both ends of the transmission film 107 and the images of the two alignment marks of the second Si wafer on the monitor 90 (ST71). The knob is adjusted to move and rotate the transmission film in the X and Y directions until the alignment marks 108 and 109 of the transmission film 107 are aligned with the alignment marks of the second Si wafer (ST72). The transmission film 107 is addressed to the second Si wafer on the stage while aligning the alignment marks 108 and 109 of the transmission film 107 with the alignment marks of the second Si wafer (ST73).
[0073]
Next, a paste-like adhesive is applied to the permeable membrane 107 in the same manner as in the figure showing the adhesive application step (ST12) in FIG. Thereafter, the adhesive is spread by applying pressure with a spatula or the like, so that the adhesive penetrates through the resist-free eyes of the permeable film. As a result, the adhesive is reliably applied only to the periphery of the contact portion of the second Si wafer 24, and the adhesive is applied to a uniform thickness without interruption (ST74). Thereafter, the stage B is slid to separate the permeable film from the second Si wafer (ST75).
[0074]
At this time, as in the cross section of the Si wafer shown in FIG. 17, the adhesive layer 46 is accurately applied to the surface of the second Si wafer 24 other than the contact portion.
[0075]
Next, the first Si wafer 23 is fixed with the claw of the stage C (ST76). In this state, the infrared light source 88 is turned on, and the infrared camera 89 is operated. At this time, the infrared rays pass through the first Si wafer and the second Si wafer, and the images of the alignment marks at both ends of both Si wafers are displayed on the monitor 90 (ST77).
[0076]
The images at that time are shown in the same manner as in FIGS. 21 (a), (b) and (c). The alignment marks 28 on the first Si wafer 23 are rotated in the X and Y directions by the knobs 99, 101, and 104 until the alignment marks 29 on the second Si wafer overlap with each other and become aligned as shown in FIG. Then, it is moved (ST78). 21C is when the surfaces of the first Si wafer and the second Si wafer coincide with each other. At this time, the nail 98 is moved, the wafer is detached from the nail 98, and the second Si wafer is removed. Is bonded to the first Si wafer 24 and the first Si wafer 23 (ST79).
[0077]
As a result, the first Si wafer 23 and the second Si wafer 24 are bonded to each other as in the case shown in FIG. 24, and the gas passage 70 is accurately formed.
[0078]
In the specific example 3, as in the specific examples 1 and 2, the joined body 69 is cut out and subdivided to complete a plurality of semiconductor members for a gas rate sensor. At this time, by making a cut in advance in a portion to be cut into the first Si wafer or the second Si wafer, the semiconductor member is easily divided into one by the cleavage of the semiconductor, and the semiconductor member is subdivided. be able to.
[0079]
By using this method for manufacturing a semiconductor gas rate sensor, the gas tightness is maintained, the adhesive does not protrude, the number of members required for the process is small, and the productivity is high in the manufacturing process without complexity. Can be manufactured.
[0080]
Next, FIG. 31 is a flowchart showing a manufacturing process in the second embodiment of the method for manufacturing a semiconductor gas rate sensor according to the present invention. In this method for manufacturing a semiconductor gas rate sensor, the formation of an alignment mark on a first Si wafer and the formation of a heat wire bridge having a heat wire and a half-groove serving as a gas passage on the first Si wafer are performed. A step of simultaneously performing the step (ST80), a step of forming a half groove for forming a gas groove in the second Si wafer, and a step of forming an alignment mark (ST81); the first Si wafer or the second Si wafer; A permeable membrane addressing step (ST82) in which a transmission area through which the adhesive is transmitted is provided on the bonding surface of the wafer (ST82), and a shape in accordance with the transmission area by transmitting the adhesive from above the permeable membrane. Applying an adhesive to the bonding surface of the first Si wafer or the second Si wafer (ST83), and bonding the bonding surface of the first Si wafer and the bonding surface of the second Si wafer. And adhering Te Align (ST 84), the step of subdividing cut out Si wafer bonded body formed by these steps (ST85), the semiconductor element is fabricated for semiconductor gas rate sensor. By attaching a piezo pump or the like to the semiconductor member for the semiconductor gas rate sensor, a semiconductor gas rate sensor can be obtained.
[0081]
Next, each step will be described in detail. FIG. 32 is a flowchart showing a step (ST80) of simultaneously forming an alignment mark and a contact portion on the first Si wafer. In this step, an insulating film forming step (ST90) for forming an insulating film made of SiN on the (100) plane of the Si wafer and a metal for forming a thin metal resistance layer by depositing a heat-sensitive resistor such as platinum on the insulating film. A resistive layer thin film forming step (ST91) and a heat wire and electrode forming step of forming a heat wire by etching the metal resistive layer into a predetermined shape to form a heat wire, and also forming electrode portions on both sides thereof (FIG. ST92), a protective film forming step of forming a protective film made of SiN from above the heat wire and the electrode (ST93), and a heat treatment step of performing a heat treatment for suppressing a temporal change of the heat-sensitive resistance characteristic of the heat wire itself (ST93). ST94) and etching the first Si wafer to form a half hole, a half groove and an alignment mark. The Si portion is removed by etching consists of etching process for forming a heat-wire bridge (ST95) by.
[0082]
The insulating film forming step (ST90), the metal resistive layer thin film forming step (ST91), the heat wire and electrode forming step (ST92), the protective film forming step, and the heat treatment step are the same as those in the first embodiment.
[0083]
As shown in FIG. 33, in the etching step, after applying a resist on the entire surface of the first Si wafer, the resist corresponding to the half holes, the half grooves and the alignment marks is removed (a), and the openings 115 and 116 are formed. Is formed, and the SiN 117 at that portion is etched (b). FIG. 34 shows the surface of the alignment mark at that time. A removed portion 118 of SiN is formed.
[0084]
Next, the first Si wafer is subjected to anisotropic etching of Si using an etchant such as KOH. Thereby, as shown in FIGS. 33 (c) and 35, the etching is selectively performed on the (111) plane, and the etching depth is small in the alignment mark portion 119 where the area of the opening 116 is small. It can be seen that the etching depth of the portion 120 where the area of the opening 115 is large and where the contact portion is formed is large. Thereby, it is possible to simultaneously form the contact portion 120 serving as a gas passage and the alignment mark 119.
[0085]
Next, FIG. 36 shows a step of simultaneously forming a contact portion on the second Si wafer. This step includes an insulating film forming step (ST100) of forming an insulating film made of SiN on the (100) plane of the Si wafer, and etching for forming a half hole, a half groove and an alignment mark by etching the second Si wafer. It comprises a step (ST102).
[0086]
The insulating film forming step (ST100) is the same as the step for the first Si wafer.
[0087]
In the etching step (ST102), a portion corresponding to the half hole, the half groove, and the alignment mark is opened, a resist is applied, and the SiN in that portion is etched (ST101). FIG. 37 shows the surface of the alignment mark at that time. An SiN etching portion 121 and a portion 122 having SiN are formed.
[0088]
Next, anisotropic etching of Si is performed using an etchant such as KOH. Accordingly, as shown in FIG. 38, the etching is performed so that the (111) plane comes out. When the (111) plane is overlapped, the etching is stopped, and in the alignment mark part having a small opening area, the etching depth is reduced. The etching depth becomes deep in the portion where the contact portion is formed shallow and has a large opening area. Thereby, the contact portion serving as the gas passage and the alignment mark can be simultaneously formed.
[0089]
In this manner, a step of addressing a transmission film in which the alignment mark and the engraved portion are formed, and the transmission surface is provided with a transmission range through which the adhesive is transmitted to the bonding surface of the first Si wafer or the second Si wafer. Subsequent steps are performed in the same manner as in the first embodiment. Accordingly, a semiconductor gas rate sensor can be manufactured with high airtightness, no protrusion of the adhesive, few components required in the process, and high production efficiency in a less complicated manufacturing process.
[0090]
Note that the resist used in the present embodiment is a positive type resist, but can be performed using a negative type resist.
[0091]
Note that, in the embodiment of the present invention, the description has been made using the paste adhesive, but the adhesive may be applied using a spray adhesive. At this time, the adhesive can be applied without applying pressure to the adhesive with a spatula or the like. Further, although the Si substrate is used as the semiconductor substrate, the bonding may be performed using another semiconductor substrate. Further, in the embodiment of the present invention, the production of the gas rate sensor has been described. However, in addition to the gas rate sensor, a semiconductor substrate for a micromachining element such as a pressure sensor or a gas sensor can be suitably joined.
[0092]
【The invention's effect】
As apparent from the above description, the present invention has the following effects.
[0093]
Since bonding is not performed between chip components but in a wafer state during a process, bonding can be performed with high accuracy. That is, since the alignment mark provided for alignment with the element configured as the chip component is integrally formed on the wafer and the alignment is performed based on the alignment mark, the elements configured as the chip component are positioned with respect to each other. The factor of causing a gap is eliminated. Thus, the complexity of the manufacturing process can be avoided, and the productivity can be increased. In addition, since the alignment marks are read through infrared rays and read and the alignment of the Si wafer is performed, two Si wafers can be bonded accurately.
[0094]
Furthermore, an adhesive is applied from above the permeable film, a shape according to the transmission range is applied to one adhesive surface of the semiconductor substrate, and the other semiconductor substrate is attached and adhered thereto. If the agent is of a thermosetting type, since the adhesive can be immediately cured after the application of the adhesive, it is possible to avoid the complexity of the manufacturing process, which requires heating in multiple steps as in the conventional technology. be able to. In addition, even if the semiconductor substrate has a contact portion and the bonding surface has a more complicated shape, the bonding operation can be performed smoothly. Further, since a large number of semiconductor members can be smoothly bonded at one time, an extremely efficient bonding operation can be provided when a large number of semiconductor members are obtained from one semiconductor substrate.
[0095]
Since the bonding surface is the (100) plane, good anisotropic etching can be performed.
[0096]
Since the etching process of the alignment mark and the gas passage is performed at once from the resist patterning, the positional relationship between the alignment and the gas passage can be improved in accuracy as compared with the case where the alignment and the gas passage are bonded in a chip component state. In addition, the sensing performance can be improved with the improvement of the accuracy of the shape of the gas passage and the position of the heat sensor.
.
[0097]
The control in the depth direction is enabled by the shape of the mask pattern on the (100) plane. For a wafer thickness of 700 microns, the depth of the half groove of the gas passage is 420 microns and is several tens of microns. Thus, it is possible to prevent the wafer from being cracked due to the reduction in the wafer strength due to the unnecessary formation of the contact portion.
[Brief description of the drawings]
FIG. 1 is an exploded perspective view of a semiconductor member for a gas rate sensor manufactured using a method for manufacturing a semiconductor gas rate sensor according to the present invention.
FIG. 2 is a schematic diagram illustrating a configuration of a gas rate sensor.
FIG. 3 is a flowchart showing a manufacturing process in the first embodiment of the method for manufacturing a semiconductor gas rate sensor of the present invention.
FIG. 4 is a flowchart showing a process of forming an alignment mark on a first Si wafer and a second Si wafer.
FIG. 5 is a cross-sectional view of the Si wafer in a state where a resist is applied.
FIG. 6 is a cross-sectional view of a first Si wafer and a second Si wafer in which a resist opening is formed.
FIG. 7 is a cross-sectional view of a first Si wafer and a second Si wafer on which alignment marks are formed.
FIG. 8 is a diagram showing a first Si wafer (a) having a first alignment mark and a second Si wafer (b) having a second alignment mark.
FIG. 9 is a flowchart showing a process of forming a heat wire bridge having heat wires and a half groove serving as a gas passage on a first Si wafer.
FIG. 10 is a cross-sectional view of a first Si wafer, (a) a state where SiN is deposited, (b) a state where platinum is deposited on SiN, (c) a state where platinum is patterned, and (d). The state where the SiN layer is formed on the patterned platinum, and (e) the state where the half groove and the heat wire bridge are formed.
11A and 11B are diagrams illustrating a first Si wafer having a manufactured functional unit, wherein FIG. 11A illustrates a first Si wafer, and FIG. 11B illustrates a shape of one etching unit.
FIG. 12 is a flowchart illustrating a process of forming a half groove in a second Si wafer.
13A and 13B are cross-sectional views of a second Si wafer, wherein FIG. 13A is a state where a resist is applied, FIG. 13B is a state where a resist opening is formed, and FIG. It has been done.
FIGS. 14A and 14B are diagrams showing a second Si wafer having a scribed portion and an alignment mark, wherein FIG. 14A shows the entire Si wafer and FIG. 14B shows a single scribed portion;
FIG. 15 is a perspective view showing a step of assigning a permeable film to a Si wafer in the first specific example.
FIG. 16 is a partially enlarged view of a permeable membrane.
FIG. 17 is a cross-sectional view of a substrate fixing part.
FIG. 18 is a perspective view showing an adhesive application step.
FIG. 19 is a sectional view of a second Si wafer to which an adhesive has been applied.
FIG. 20 is a view showing an alignment apparatus used in a bonding step of a first Si wafer and a second Si wafer.
FIG. 21 is a view showing an alignment apparatus used in a bonding step of a first Si wafer and a second Si wafer.
FIG. 22 is a flowchart showing a procedure for bonding a first Si wafer and a second Si wafer using an alignment apparatus.
23A and 23B are diagrams showing images of alignment marks, wherein FIG. 23A is an alignment mark of a first Si wafer, FIG. 23B is an alignment mark of a second Si wafer, and FIG. 2 shows an image of an alignment mark of a first Si wafer and an alignment mark of a second Si wafer projected by an infrared camera.
FIG. 24 is a cross-sectional view after bonding the first Si wafer and the second Si wafer.
FIG. 25 is a view showing an alignment apparatus used in an adhesive application step and a bonding step of a first Si wafer and a second Si wafer in a second specific example.
FIG. 26 is a flowchart showing a procedure for applying an adhesive using an alignment apparatus and a procedure for bonding a first Si wafer and a second Si wafer in a second specific example.
FIG. 27 is a view showing an alignment apparatus used in an adhesive application step and a bonding step of a first Si wafer and a second Si wafer in a third specific example.
FIG. 28 is a view showing a stage used in an adhesive application step and a step of bonding a first Si wafer and a second Si wafer in a third specific example.
FIG. 29 is a perspective view showing an operation procedure in each step in the third specific example.
FIG. 30 is a flowchart showing a manufacturing process in a third specific example.
FIG. 31 is a flowchart showing a manufacturing process in a second embodiment of the method for manufacturing a semiconductor gas rate sensor of the present invention.
FIG. 32 is a flowchart showing a process of simultaneously forming an alignment mark and a contact portion on a first Si wafer.
FIG. 33 is a cross-sectional view of a first Si wafer, in which (a) a state in which a resist opening is provided in a portion corresponding to a half groove and an alignment mark, (b) a state in which SiN is partially etched, and (c). This shows a state in which a half groove and an alignment mark are formed.
FIG. 34 is a diagram showing a state in which SiN in a portion where a first alignment mark is to be formed has been removed.
FIG. 35 is a diagram showing a first alignment mark.
FIG. 36 is a flowchart showing a process of simultaneously forming a contact portion on a second Si wafer.
FIG. 37 is a diagram showing a state in which SiN in a portion where a second alignment mark is to be formed has been removed;
FIG. 38 is a diagram showing a second alignment mark.
[Explanation of symbols]
10. Semiconductor members for gas rate sensors
11 Lower semiconductor substrate
12 Upper semiconductor substrate
13,14 Heat wire
15 Heat wire bridge
16, 17 Contact part
18 Gas rate sensor
19 Sensor chip
20 Piezo pump
21 Gas introduction unit
22 Inlet of gas passage
23 First Si Wafer
24 Second Si Wafer
28 First alignment mark
29 Second alignment mark
43 Adhesive transmission device
46 permeable membrane
56 Alignment device
ST10 Step of forming alignment mark
ST11 Having heat wires on first Si wafer
Heat wire bridge and gas channel half groove
Functional part formation process to be formed
ST12 Form a half groove serving as a gas passage in the second Si wafer
Half groove forming process
ST13 Step of assigning a permeable membrane to a permeable membrane
ST14 Step of applying adhesive to joint surface
ST15 Bonding surface of first Si wafer and second Si wafer
Bonding process by joining the bonding surfaces of
ST16 Extraction of gas rate sensor

Claims (5)

In a method for manufacturing a semiconductor gas rate sensor for providing a heat wire bridge having a detection unit consisting of a pair of heat wires in a gas passage and detecting an angular velocity from a bias of a gas flow hitting the heat wire,
A first alignment mark forming step of forming a plurality of first alignment marks on a bonding surface of the first Si wafer;
A second alignment mark forming step of forming a plurality of second alignment marks on the bonding surface of the second Si wafer;
A functional part forming step of forming the heat wire bridge having the detecting part composed of the pair of heat wires and the half groove serving as the gas passage on the first Si wafer;
A half-groove forming step of forming a half-groove serving as the gas passage in the second Si wafer;
A permeable membrane addressing step for addressing a permeable membrane provided with a permeable area for allowing an adhesive to pass through a bonding surface of the first Si wafer or the second Si wafer;
Applying the adhesive to the bonding surface of the first Si wafer or the second Si wafer in a shape according to the transmission range by transmitting the adhesive from above the permeable film;
The first alignment mark of the first Si wafer and the second alignment mark of the second Si wafer are read by transmitting infrared rays, and the first alignment mark and the second alignment mark are read. Bonding a bonding surface of the first Si wafer and a bonding surface of the second Si wafer in accordance with a predetermined position;
A method for manufacturing a semiconductor gas rate sensor, comprising: 2. The method for manufacturing a semiconductor gas rate sensor according to claim 1, wherein a (100) plane is used as a bonding surface between the first Si wafer and the second Si wafer. 2. The method of manufacturing a semiconductor gas rate sensor according to claim 1, wherein the half groove serving as the gas passage of the first Si wafer and the first alignment mark are simultaneously formed by wet etching. 2. The method for manufacturing a semiconductor gas rate sensor according to claim 1, wherein the half groove serving as the gas passage of the second Si wafer and the second alignment mark are simultaneously formed by wet etching. A mask pattern is placed on the (100) plane of the first Si wafer or the (100) plane of the second Si wafer, and anisotropic wet etching is performed. The method for manufacturing a semiconductor gas rate sensor according to claim 3, wherein the engraved portion is formed along the <111> direction of the Si wafer.

Images