JP2010087280A - Manufacturing method of functional device and manufacturing method of semiconductor device, which uses functional device manufactured by the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a functional device which is superior in mass production and can improve performance without damaging the functional device at the time of manufacturing, and to provide a manufacturing method of the semiconductor device using the method. <P>SOLUTION: In the manufacturing method of the functional device 10, a hollow 5 which spatially separates a part of a functional thin film 2 formed on one surface of a silicon substrate (substrate) 1 is formed in the silicon substrate 1. When forming and separating the functional device 10 on one surface of a silicon wafer (wafer) 3 becoming a base, a dicing sheet 7 is stuck to the other surface of the silicon wafer 3 and a temporary fixing sheet 6 is directly stuck to one surface. The silicon wafer 3 is cut from a temporary fixing sheet 6, the temporary fixing sheet 6 is peeled from the functional device 10 and then organic substances existing on surfaces of the functional devices 10 are removed by dry processing in the manufacturing method of the functional device. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention provides a functional device that can provide a functional device with stable quality and excellent mass productivity when a functional thin film is formed by cutting a wafer with a dicing blade to produce a plurality of functional devices. The present invention relates to a method and a manufacturing method of a semiconductor device using a functional device manufactured thereby.

  Conventionally, a high-frequency device as a functional device has a substrate and a functional thin film formed on one surface side of the substrate, and a cavity that spatially separates a part of the functional thin film from the substrate is formed. Functional devices such as devices, thermal infrared sensors, and various MEMS (Micro Electro Mechanical Systems) devices (for example, acceleration sensors, gyro sensors, ultrasonic sensors, micro valves, etc.) are known. In manufacturing such a functional device, a number of functional devices are formed on the wafer serving as the basis of the above-mentioned substrate using micromachining technology, and then separated into individual functional devices from the wafer. is doing.

  Here, when separating from the wafer into individual functional device chips, it is common to perform dicing to cut the wafer into a lattice while rotating a blade holding diamond abrasive grains with a binder at high speed. At the time of full cutting to completely cut the active device, a dicing sheet is pasted on the wafer in advance so that the chips after cutting are not separated, and the wafer ring holding the dicing sheet is vacuum sucked to the dicing stage of the dicing machine . Also, during dicing, pure water is sprayed to remove chips from the wafer and to cool the blade. However, compared to other electronic devices such as IC and LSI, functional devices in which a part of the functional thin film is spatially separated from the substrate are fragile. When dicing a wafer, the above wafer ring is diced. The functional device may be damaged due to the pressure of pure water for cooling the blade used during vacuum suction to be fixed to the stage or dicing. Therefore, a dicing sheet is affixed to the other surface side of the wafer on which many functional devices having a functional thin film are formed on one surface side, and a protective layer made of a resin layer is formed on the one surface side of the wafer on which the functional thin film is formed. A technique for dicing in the provided state and removing the protective layer after cutting has been proposed (see, for example, Patent Document 1).

  By the way, in the dicing method described in the above-mentioned Patent Document 1, it is disclosed that an adhesive protective sheet may be provided on the surface side of the wafer where the functional thin film is formed instead of the protective layer made of resin. As a sheet, a surface protection sheet to be applied to protect the circuit formation surface during grinding of the wafer back surface in a normal LSI manufacturing process, an ultraviolet peeling type that can be peeled off due to a decrease in adhesive strength due to ultraviolet irradiation, or can be peeled off by heating It is described that a low contamination type sheet such as a heat peeling type or a mixed type thereof may be used.

In addition, when such a protective layer alone cannot sufficiently protect the wafer during dicing, a protective film is provided on the resist film after forming a resist film on the wafer on which a plurality of functional devices are formed. A technique for removing a protective sheet by dissolving a resist film after cutting a wafer has been proposed (see, for example, Patent Document 2).
JP 2004-186255 A JP 2005-197436 A

  However, today's progress in device function improvement is remarkable, and in a functional device that requires high performance and thinning, the organic material of the protective sheet functions only by the manufacturing method using the protective layer and protective sheet of Patent Document 1 described above. It remains on the surface of the functional device, and a functional device with improved performance cannot be manufactured. Further, in the functional device manufacturing method disclosed in Patent Document 2, a functional device in which a cavity for spatially separating a part of a functional thin film formed on one surface side of the substrate and the substrate is formed. When a resist film is formed on the resist film, it is necessary to apply the resist onto the wafer by spin coating or the like and then thermally cure to form a resist film. However, the resist film expands and contracts during thermal curing, resulting in a functional thin film. There was a risk that the functional thin film was destroyed due to stress. Further, when the above resist film is removed by wet etching, the functional device may be destroyed.

  The present invention has been made in view of the above-mentioned reasons, and the purpose thereof is a functional device that can be a functional device that is superior in mass productivity and has improved performance without breakage of the functional device at the time of manufacture. And a method of manufacturing a semiconductor device using the functional device.

  The invention of claim 1 includes a substrate and a functional thin film formed on one surface side of the substrate, and a cavity for spatially separating a part of the functional thin film and the substrate is formed in the substrate. A functional device manufacturing method comprising: forming a plurality of functional devices having the functional thin film on one surface side of the wafer on a wafer serving as a base of the substrate, and then separating the functional devices into individual functional devices In doing so, a dicing sheet is attached to the other surface side of the wafer and a temporary fixing sheet is directly attached to the one surface side of the wafer, and after the sheet attaching step, the temporary fixing sheet side is followed by the temporary fixing sheet side. By cutting the fixed sheet and the wafer, a dicing process for forming a functional device formed into a chip on the dicing sheet, and a composite cut by the dicing process are performed. A temporary fixing sheet peeling step for peeling each of the temporary fixing sheets from the plurality of functional devices, an organic matter removing step for removing organic substances present on the surface of each functional device by a dry treatment after the temporary fixing sheet peeling step, It is a manufacturing method of the functional device which has this.

  According to the present invention, the temporary fixing sheet is directly attached to one surface side of the wafer to reinforce the functional thin film, and then the dicing is performed, and the organic substance removing step is provided after the temporary fixing sheet is peeled off. Even in a functional device on which a functional thin film is formed, there can be provided a method for producing a functional device that is superior in mass productivity and can improve performance without breakage of the functional device during production.

  The invention of claim 2 is the invention of claim 1, wherein the functional device has a slit penetrating in the thickness direction of the functional thin film and communicating with the cavity. It is a method for producing a functional device, wherein an organic substance existing in at least one of a slit or an inner surface of a cavity is removed.

  According to the present invention, even if the functional device has a slit penetrating in the thickness direction of the functional thin film and communicating with the cavity, the performance is improved by removing unnecessary organic substances attached to the functional device. Functional device.

  The invention of claim 3 is the functional device of the invention of claim 1, wherein in the temporary fixing sheet peeling step, the peeling member is fixed to the temporary fixing sheet, and then the temporary fixing sheet is peeled from the functional device together with the peeling member. It is a manufacturing method.

According to the present invention, a temporarily fixed sheet cut into a plurality of pieces using a peeling member can be peeled from a wafer at a time, and a functional device can be manufactured at low cost with good mass productivity.
Invention of Claim 4 is manufacturing invention of the functional device using the heat-peelable pressure-sensitive adhesive sheet whose adhesive strength is reduced by heating as the temporary fixing sheet in the invention of any one of Claims 1 to 3. Is the method.

  According to this invention, since the adhesive force is surely lost by heating, the functional device can be manufactured with high yield without destroying the functional thin film. In particular, the heat-peelable pressure-sensitive adhesive sheet can reduce the residual adhesive force at the time of peeling compared to the UV-peelable pressure-sensitive adhesive sheet. Therefore, in the case of a functional device having a functional thin film communicating with the cavity through a slit, the yield is high. More improved. Similarly, when compared with a water-soluble peelable pressure-sensitive adhesive sheet, the heat-peelable pressure-sensitive adhesive sheet does not need to be exposed to an aqueous solution at the time of peeling, so there is no need to consider the case where the characteristics of the functional thin film deteriorate depending on the functional device .

  The invention according to claim 5 is the functional device according to claim 4, wherein in the temporary fixing sheet peeling step, the temporary fixing sheet is peeled from the functional device by heating uniformly while applying pressure uniformly to the entire surface of the temporary fixing sheet. It is a manufacturing method.

  According to this invention, in order to uniformly apply pressure and heat, even if the temporarily fixed sheet is cut into a plurality of parts, the entire surface is surely peeled without leaving the partially fixed temporarily fixed sheet, A functional device can be manufactured with high productivity without destroying the functional thin film.

  The invention of claim 6 includes at least the functional device according to any one of claims 1 to 5, a package base on which the functional device is mounted, and a cap for sealing the package base. A method for manufacturing a semiconductor device, comprising: mounting a functional device on a package base via an adhesive layer; and thereafter sealing the cap on the package base via a sealing adhesive layer Is the method.

  According to the present invention, unnecessary organic substances generated in the manufacturing process of the functional device can be reduced, so that a semiconductor device using the functional device with improved performance can be manufactured.

  A seventh aspect of the invention is a method of manufacturing a semiconductor device according to the sixth aspect of the invention, wherein when the package base is sealed with the cap, the inside of the package constituted by the package base and the cap is vacuumed or lifted.

  According to the present invention, since unnecessary organic substances in the functional device are removed, there is no change in internal pressure due to degassing, and a semiconductor device with improved performance can be manufactured. In particular, when the sealed package substrate is evacuated, the degree of vacuum can be eliminated and a highly reliable semiconductor device can be manufactured. On the other hand, when the inside of the sealed package substrate is raised, a more reliable semiconductor device can be manufactured without inflow of atmospheric gas.

  The invention of claim 8 is the method for manufacturing a semiconductor device according to claim 7, wherein at least one of the adhesive layer and the sealing adhesive layer uses an inorganic material.

  According to this invention, an inorganic material is used for at least one of the adhesive layer and the sealing adhesive layer, and unnecessary organic substances generated in the manufacturing process of the functional device are removed in advance, so that the semiconductor device is in an airtight state. In this case, a semiconductor device in which the internal pressure does not change due to degassing can be manufactured.

  According to a ninth aspect of the present invention, there is provided a method for manufacturing a semiconductor device according to any one of the fifth to eighth aspects of the present invention, wherein the organic substances in the package base and the cap are removed in advance prior to the sealing of the package base. It is.

  According to the present invention, since the organic substances present in the package base and the cap are removed and sealed, a method for manufacturing a semiconductor device with improved performance can be provided.

  A tenth aspect of the present invention is the method for manufacturing a semiconductor device according to the ninth aspect of the present invention, wherein at least the package base is organic substance removed simultaneously with the functional device by the organic substance removing step.

  According to the present invention, after the functional device is mounted on the package base, unnecessary organic matter of the functional device and unnecessary organic matter of the package base can be removed at the same time. It can be manufactured with high productivity.

  In the invention of claim 1, in the functional device formed by spatially separating a part of the functional thin film from the substrate, the functional device is not damaged at the time of manufacture, and is excellent in mass productivity and can improve performance. There is a remarkable effect that a method for manufacturing a functional device can be provided.

  According to the invention of claim 6, it is possible to provide a semiconductor device manufacturing method capable of providing a semiconductor device in which unnecessary organic substances generated in the manufacturing process of the functional device are reduced and the performance of the functional device is improved.

(Embodiment 1)
In the present embodiment, an infrared array sensor as a functional device will be described with reference to FIG. 2, a thermal infrared sensor constituting the infrared array sensor will be described with reference to FIG. 3, and a method for manufacturing the infrared array sensor will be described with reference to FIG.

  The infrared array sensor 32 of FIG. 2 is used for an infrared image sensor or the like. FIG. 2A shows m × n (2 × 2 in the illustrated example) thermal infrared detectors 30. They are arranged in a two-dimensional array. In FIG. 2B, an equivalent circuit is shown with the thermopile constituting the thermocouple type sensing element (temperature sensing unit) 20 in the thermal infrared detector 30 as a voltage source corresponding to the thermoelectromotive force of the thermopile. is there.

  As shown in the cross-sectional view of FIG. 3B, the thermal infrared detector 30 as the thermal infrared sensor that constitutes the infrared array sensor 32 is silicon formed on one surface side of the silicon substrate 1 that is a substrate. The oxide film 11, the silicon nitride film 12 formed on the silicon oxide film 11, the sensing element 20 formed on the silicon nitride film 12, and the sensing element 20 covered with the surface side of the silicon nitride film 12 The functional thin film 2 is formed by patterning the laminated structure of the formed interlayer insulating film 17 and the passivation film 19 formed on the interlayer insulating film 17. Here, a cavity 5 is provided on the one surface side of the silicon substrate 1, and a part of the functional thin film 2 is spatially separated from the silicon substrate 1 by the cavity 5 provided in the silicon substrate 1. In addition, a slit 4 communicating with the cavity 5 is provided in the thickness direction of the functional thin film 2. A portion of the functional thin film 2 that is spatially separated from the silicon substrate 1 constitutes an infrared absorbing portion 21 that absorbs infrared rays.

  The thermal infrared detecting unit 30 includes the interlayer insulating film 17 made of a BPSG (Boro-PhosphoSilicate Glass) film, and the passivation film 19 as a PSG (Phospho Silicate Glass) film and an NSG (Non-doped Silicate Glass) on the PSG film. The laminated film of the interlayer insulating film 17 and the passivation film 19 also serves as the infrared absorption film 22. Here, when the refractive index of the infrared absorption film 22 is n and the center wavelength of the infrared ray to be detected is λ, and the thickness t of the infrared absorption film 22 is set to λ / 4n, the wavelength of the detection target (for example, 8 The absorption efficiency of infrared rays (˜12 μm) can be increased, and high sensitivity can be achieved. For example, if n = 1.4 and λ = 10 μm, then t≈1.8 μm, the thickness of the interlayer insulating film 17 is 0.8 μm, the thickness of the PSG film is 0.5 μm, and the NSG film The film thickness is 0.5 μm. Note that the passivation film 19 is not limited to the stacked film of the PSG film and the NSG film, and may be formed of, for example, a silicon nitride film. Further, the cavity 5 of the silicon substrate 1 is not limited to the one in which the depression is formed on the one surface side of the silicon substrate 1, and may be provided so as to penetrate in the thickness direction of the silicon substrate 1.

  The sensing element 20 made of the above-described thermopile includes a p-type polysilicon layer 15, an n-type polysilicon layer 13, and an infrared absorption layer formed across the infrared absorption portion 21 and the silicon substrate 1 as shown in FIG. The p-type polysilicon layer 15 and the n-type polysilicon layer 13 are electrically connected to each other on the infrared incident surface side of the portion 21, and the connection portion 23 is made of a metal material (for example, Al—Si). Here, the sensing element 20 has a metal material (for example, the other end of the p-type polysilicon layer 15 and the other end of the n-type polysilicon layer 13 of the thermocouple adjacent to each other on one surface side of the silicon substrate 1. Four of them are joined in series by a wiring 18 made of Al-Si or the like. The thermopile constituting the sensing element 20 forms a hot junction on the infrared absorption part 21 side by one end part of the n-type polysilicon layer 13, one end part of the p-type polysilicon layer 15 and the connection part 23. The other end of the layer 15, the other end of the n-type polysilicon layer 13, and the wiring 18 form a cold junction on the silicon substrate 1 side.

  Further, the infrared array sensor 32 of the present embodiment has a plurality (four in the illustrated example) of output pads 24 (Vout−) in which one end of each sensing element 20 is individually connected as shown in FIG. 1, Vout-2, Vout-3, Vout-4) and a plurality of (two in the illustrated example) thermal type infrared detectors 30 in each row, the other ends of the sensing elements 20 are commonly connected. A reference bias pad 26 (Vref) is provided so that the outputs of all the thermal infrared detectors 30 can be read in time series. The sensing element 20 made of a thermopile is connected to a common reference bias line 29 having one end electrically connected to the output pad 24 via the vertical readout line 27 and the other end connected to the reference bias pad 26. It is electrically connected via a reference bias line 28. Here, for example, if the potential of the reference bias pad 26 (Vref) is set to 1.65 V, each thermal infrared ray is output from the output pad 24 (Vout-1, Vout-2, Vout-3, Vout-4). The detection unit 30 can be read out as the output voltage of the pixel A (1.65 V + output voltage of the sensing element 20).

  Further, the connection portion 23 formed of a metal material is electrically connected to the n-type polysilicon layer 13 and the p-type polysilicon layer 15 through contact holes 25 formed in the interlayer insulating film 17, respectively. . The cavity 5 provided in the silicon substrate 1 causes thermal separation in the functional thin film 2 and improves the sensitivity of the thermal infrared sensor. In the cavity 5 of the silicon substrate 1, for example, slits 4 penetrating in the thickness direction of the functional thin film 2 are formed at the four corners of a rectangular region serving as the infrared absorbing portion 21, and the slit 4 is used as an etching solution introduction hole. An etching solution (for example, an aqueous TMAH (tetramethylammonium hydroxide) solution or an aqueous KOH (potassium hydroxide) solution) that is an alkaline solution is added and the silicon substrate 1 is anisotropically etched. Such a slit 4 contributes to improving the sensitivity of the thermal infrared sensor by thermally separating the thermocouples. Note that the shape of the slit 4 is not limited to a rectangle, but can be variously selected as desired, such as a triangle, an ellipse, and a circle. Furthermore, in this embodiment, the n-type compensating polysilicon layer 14 and the p-type that are not electrically connected to the infrared incident surface side of the infrared absorbing portion 21 when the n-type polysilicon layer 13 and the p-type polysilicon layer 15 are patterned. The compensation polysilicon layer 16 is left. The n-type compensation polysilicon layer 14 and the p-type compensation polysilicon layer 16 improve the uniformity of the stress balance of the functional thin film 2 and prevent warping while reducing the thickness of the functional thin film 2 to prevent thermal infrared rays. Since the sensitivity of the sensor can be improved, it can be preferably provided. The thickness of the functional thin film 2 laminated in this way is sufficiently thinner than the thickness of the silicon substrate 1.

  Hereinafter, a method for manufacturing the functional device 10 including the above-described infrared array sensor 32 will be described with reference to FIGS. 1 and 4, but it is not limited to this embodiment as long as the effects of the present invention are achieved. Not too long.

  First, the above-described functional thin film 2 is formed on one surface side of a silicon wafer 3 which is a wafer serving as a base of a silicon substrate 1 which is a substrate. Subsequently, a slit 4 is formed in the functional thin film 2 to form a thermal infrared sensor by photolithography technique and etching technique. By introducing an etching solution from the slit 4, anisotropic etching is performed on the silicon substrate 1 to form a plurality of cavities 5 corresponding to the thermal infrared sensors. Thus, a large number of functional devices 10 are formed on the one surface side of the silicon wafer 3. Subsequently, a dicing sheet 7 (see FIG. 4) is pasted on the other surface side opposite to the one surface side where the functional thin film 2 is formed on the silicon wafer 3 on which many functional devices 10 are formed. A structure shown in FIG. 1A is obtained by performing a sheet sticking step of directly sticking the temporary fixing sheet 6 (see FIG. 4) to the one surface side of the silicon wafer 3. For the purpose of protecting the functional thin film 2 first, the sheet fixing process is performed by first bonding the temporary fixing sheet 6 to the functional thin film 2 side of the silicon wafer 3 and subsequently bonding the dicing sheet 7. It is also possible (FIG. 1 (a)).

  Here, in this embodiment, as the temporary fixing sheet 6, a sheet in which an adhesive is applied on a base material such as plastic or polyester having a thickness of about 1 to 500 μm is suitably used. The temporary fixing sheet 6 is preferably one that can protect the functional thin film 2 and the like from cutting stress or stress generated by cooling and washing during dicing of the silicon wafer 3 and does not interfere with cutting of the silicon wafer 3. .

  Therefore, as the temporary fixing sheet 6, an ultraviolet peelable pressure-sensitive adhesive sheet whose adhesive strength is reduced by irradiating with ultraviolet light, a water-soluble peelable pressure sensitive adhesive sheet whose adhesive strength is reduced when immersed in an aqueous solution, or an adhesive strength which is reduced by heating. A heat-peelable pressure-sensitive adhesive sheet can be suitably used. In view of reducing the adhesive force in a short time in view of mass productivity, the heat-peelable pressure-sensitive adhesive sheet or the UV-peelable pressure-sensitive adhesive sheet is preferable to the water-soluble peelable pressure-sensitive adhesive sheet. In view of the adhesive strength after the treatment, the heat-peelable pressure-sensitive adhesive sheet is less preferable than the UV-peelable pressure-sensitive adhesive sheet, and is more preferable in terms of easy peeling without damaging the functional thin film 2. . As the heat-peelable pressure-sensitive adhesive sheet, a pressure-sensitive adhesive containing thermally expandable fine particles (for example, rubber pressure-sensitive adhesive, acrylic pressure-sensitive adhesive, vinyl alkyl ether pressure-sensitive adhesive, silicone pressure-sensitive adhesive, polyester pressure-sensitive adhesive, polyamide-based pressure sensitive adhesive) A material obtained by applying a pressure-sensitive adhesive, a urethane-based pressure-sensitive adhesive, a fluorine-based pressure-sensitive adhesive, etc. to a base material such as polyester can be used. Examples of the heat-expandable fine particles include microcapsules in which a substance that easily expands by gasification by heating, such as isobutane, propane, and pentane, is encapsulated in an elastic shell.

  In attaching the temporary fixing sheet 6 to the one surface side of the silicon wafer 3, the temporary fixing sheet 6 is disposed on the one surface side of the silicon wafer 3 and is appropriately attached by a rubber roller, a spatula, a press, or a combination thereof. Just add. Further, in the present embodiment, a sheet-like sheet is used as the temporary fixing sheet 6, but a tape-shaped sheet may be used and continuously attached to a plurality of silicon wafers 3 by the Roll to Roll method. Good.

  After the above-described sheet pasting step, the other surface side of the silicon wafer 3 on which the functional thin film 2 of the silicon wafer 3 is not formed and the flat ring are pasted by the dicing sheet 7 by a normal method to perform wafer mounting. Then, the dicing sheet 7 side is fixed by vacuum suction on the dicing stage of the dicing apparatus together with the flat ring (not shown).

  Next, as a dicing step, a dicing blade rotated from the temporarily fixed sheet 6 side of the silicon wafer 3 is applied to cut the silicon wafer 3 together with the temporarily fixed sheet 6 along the street on the silicon wafer 3 (full cut). . In a state where the temporary fixing sheet 6 is adhered to the functional thin film 2 of each functional device 10 cut on the dicing sheet 7, the respective functional devices 10 are separated and formed into chips by the dicing grooves 8 (FIG. 1 ( b)).

  When dicing the silicon wafer 3, a dicing blade having a thickness of several tens of μm is rotated at a high speed of about 3000 to 4000 rpm, and pure water is sprayed for cleaning in order to cool the dicing blade and remove cutting waste ( Not shown). After cutting, the functional device 10 that is fully cut together with the dicing sheet 7 fixed to the flat ring is taken out from the dicing apparatus. Depending on the material and structure of the functional device 10, half-cutting may be sufficient.

  Next, a temporary fixing sheet peeling process is performed. In this temporary fixing sheet peeling step, the temporary fixing sheet 6 cut into a plurality of pieces by dicing is removed from the functional thin film 2 side of each functional device 10, so that each flat ring on which the dicing sheet 7 is pasted is provided with the temporary fixing sheet 6. The temporarily fixed sheet 6 that has been cut can be easily peeled off by performing an ultraviolet irradiation process, an aqueous solution charging process, a heating process, or the like according to the characteristics. Here, in the case of a heat-peelable pressure-sensitive adhesive sheet, the temporarily fixed sheet 6 cut individually can be peeled by heating with a hot air dryer, a hot plate, a near infrared lamp, or the like. Preferably, a plate in which a heater is incorporated in a metal plate having excellent heat conductivity is used as the peeling member 9, and the temporarily fixed sheet 6 that has been cut is pressed against the peeling member 9 and uniformly heated while applying pressure uniformly. (For example, 120 ° C., 1 minute).

  As a result, the heat-expandable fine particles contained in the pressure-sensitive adhesive of the heat-peelable pressure-sensitive adhesive sheet greatly swell to produce fine irregularities on the surface of the pressure-sensitive adhesive layer, and the temporary fixing sheet 6 and the functional thin film 2 of the silicon wafer 3 Changes from a relatively strong bond bonded at the surface to a point bond. The adhesion area of the temporary fixing sheet 6 can be reduced and the adhesive force can be greatly reduced. Thereafter, the temporary fixing sheet 6 is sucked and fixed from the pores provided in the peeling member 9 and lifted together with the peeling member 9 from the functional thin film 2 side of the silicon wafer 3 so that the functional device 10 is not easily destroyed. The temporary fixing sheet 6 can be peeled off (FIG. 1 (c)).

  Subsequently, in the present invention, an organic substance removing step is performed to remove organic substances in the plurality of functional devices 10 that are separated from each other by cutting the plurality of temporarily fixed sheets 6 cut and fixed on the dicing sheet 7. This is a functional device 10 that can improve performance by removing unnecessary organic substances adhering to the surface of the functional device 10 by dry treatment after the individually cut temporary fixing sheet 6 is peeled off. be able to. Moreover, when the functional device 10 has the slit 4 penetrating in the thickness direction of the functional thin film 2 and communicating with the cavity 5, an organic substance attached to at least one of each slit 4 or the inner surface of the cavity 5 is preferably used. Can be removed. The organic substance removing step of the present invention includes removing unnecessary organic substances by using ozone generated by irradiating ultraviolet gas or high frequency microwave to oxygen gas (FIG. 1 (d)).

  The ultraviolet ozone (UV ozone) cleaning method used as such an example is a photosensitive process using short wavelength ultraviolet rays, and unnecessary organic substances are decomposed by absorbing the short wavelength ultraviolet rays. When oxygen molecules are irradiated with ultraviolet rays having a wavelength of 184.9 nm, ozone is formed. When ozone is irradiated with ultraviolet rays having a wavelength of 253.7 nm, it is decomposed and simultaneously generates active oxygen. Most of the UV at 253.7 nm is absorbed by hydrocarbons and ozone. The product resulting from the decomposition of the organic molecules reacts with active oxygen, becomes volatile molecules, and is detached from the functional device 10. When both wavelengths of 184.9 nm and 253.7 nm exist, oxygen elements continue to be generated and become ozone and decomposed.

More specifically, unnecessary organic substances attached to the inside of the slit 4 on the surface of the functional device 10 or the cavity 5 provided in the silicon substrate 1 by causing the functional device 10 from which the temporary fixing sheet 6 has been peeled off to be processed. Can be removed by decomposition surface desorption. As such a UV ozone cleaning method, a low-pressure mercury lamp that emits light of 185 nm and 254 nm can be suitably used in a sealing apparatus for UV ozone cleaning. Oxygen (O ₂ gas) is exhausted while flowing at 1 to 20 L / min (for example, 5 L / min) in the hermetic treatment apparatus and maintained at normal pressure. Moreover, it is preferable to set from the room temperature to 350 degreeC (for example, 150 degreeC) inside the sealing processing apparatus for UV ozone washing | cleaning, and what is necessary is just to set processing time in the range of 1-120 minutes suitably.

  The functional device 10 can be further subjected to an ashing process. In this case, after the functional device 10 is arranged on the wafer holder in the chamber of the ashing apparatus, oxygen is standardized in the chamber at 1 to 1000 cc / min (sccm) (for example, 2 cc / min (sccm)) as the ashing condition. The air is exhausted while flowing, and the pressure in the chamber is set to 13 to 266 Pa (for example, 104 Pa). After the temperature of the wafer holder is stabilized at room temperature to 250 ° C. (for example, 180 ° C.), RF power is supplied to 100 to 1 kW (for example, 450 W) for 1 to 120 minutes (for example, 60 minutes) to perform ashing processing. be able to.

  Thereafter, the chips diced using a chip bonder or the like are peeled off from the dicing sheet 7 and used as individual functional devices 10 (FIG. 1 (e)).

  The infrared array sensor 32, which is the functional device 10 manufactured by such a method, has no damage to the functional thin film 2, and there is no change in thermal characteristics due to unnecessary organic substances attached to the surface of the functional device 10. The highly sensitive infrared array sensor 32 can be manufactured with high productivity. Furthermore, the infrared array sensor 32 taken out from the silicon wafer 3 and having uniform sensor characteristics between the infrared array sensors 32 can be manufactured.

(Embodiment 2)
In the second embodiment, a configuration example of the semiconductor device of the present invention is shown in FIG. 5, its functional description is shown in FIG. 6, and its manufacturing process is shown in FIG. An infrared array sensor 32 having four thermal infrared detectors 30 described in the first embodiment, and a signal processing IC that cooperates with the infrared array sensor 32 that is formed separately from the infrared array sensor 32 and is the functional device 10. The chip 33 is formed by using an adhesive layer 37 (for example, glass, AuSi, or solder. An epoxy resin can be preferably used if it is an organic material, but an inorganic material is more preferable). As shown in the figure, they are adhered and fixedly arranged in the package base 36. Specifically, the back surface of the infrared array sensor 32 and the back surface of the signal processing IC chip 33 are bonded to the package base 36 made of metal by solder. In addition, each output pad 24 and reference bias pad 26 of the infrared array sensor 32 and each input pad 31 of the signal processing IC chip 33 are individually wired with wires 35 (for example, gold wires or aluminum wires). Bonding and electrical connection are made (FIG. 7A).

  In order to efficiently electrically connect the output pad 24 and the reference bias pad 26 of the infrared array sensor 32 and the input pad 31 of the signal processing IC chip 33 with the wire 35 by the wire bonding apparatus, it is seen in a plan view. The output pads 24 and the reference bias pads 26 are arranged on one side of the rectangular infrared array sensor 32, and similarly face the sides where the output pads 24 and the like of the infrared array sensor 32 are arranged. Each input pad 31 is arranged on one side of the signal processing IC chip 33. In this way, when the input pad 31 of the signal processing IC chip 33 is mounted adjacent to the output pad 24 of the infrared array sensor 32, the wiring length of the wire 35 can be shortened and the influence of external noise can be reduced. Therefore, it is possible to make the semiconductor device 40 of high quality that is not easily received. The signal processing IC chip 33 is output from each output pad 24 (Vout-1, Vout-2, Vout-3, Vout-4) and reference bias pad 26 (Vref) of the infrared array sensor 32 as shown in FIG. The power is received by each input pad 31 (Vin-1, Vin-2, Vin-3, Vin-4) on the signal processing IC chip 33 side, and the signal is selectively sequentially transmitted by the multiplexer (MUX) and the amplifier circuit (AMP). Is extracted and amplified. In the second embodiment, at least the package base 36 has the organic substance removed at the same time as the infrared array sensor 32, which is a functional device, by the organic substance removing step (FIG. 7B). The signal processing IC chip 33 may remove unnecessary organic substances by an organic substance removing step simultaneously with the infrared array sensor 32 and the package base 36, or may separately remove organic substances.

  Such an ashing process as an organic substance removing step can be applied as needed depending on the size, number, and materials used of the infrared array sensor 32 and the signal processing IC chip 33 arranged in the package substrate 36. An ozone ashing device or a plasma ashing device can be used as photoexcited ashing.

  Next, in order to form the semiconductor device 40 by sealing the upper surface of the ashed package base 36 with a cap 39, a cap 39 made of silicon is used by using glass as a sealing adhesive layer 38 on the edge of the package base 36. It has been adhesively cured (FIG. 7C).

  The cap 39 and the package base 36 may be separately removed from the organic matter in the same manner as in the organic matter removing step of the first embodiment.

Such a sealing adhesive layer 38 used for sealing may be made of AuSi, solder, or an epoxy resin if it is organic, instead of glass. When sealing with the cap 39 after the ashing process, the oxygen flowed at the time of ashing is stopped in the vacuum processing apparatus, and the inside of the package base 36 is vacuum sealed so as not to be contaminated, or each function in place of the oxygen flowed at the time of ashing. The package base 36 and the cap 39 are sealed in a pressurized state with a gas (eg, an inert gas such as Ar gas or nitrogen gas (N ₂ )) that does not substantially affect the exposure to the device 10 or the like. It is also possible to seal by lifting pressure (higher than atmospheric pressure). The package base 36 hermetically sealed by raising the pressure does not flow in gas from the atmosphere, and a highly reliable semiconductor device 40 can be realized.

  In the second embodiment, since the infrared array sensor 32 is used, a silicon material that can transmit infrared rays is preferably used as the material of the cap 39. In the case where a visible light sensor is used instead of the infrared array sensor 32 as the functional device 10 disposed in the package base 36, a glass material is used as the cap 39, and the functional device 10 such as metal is used in the other functional devices 10. Needless to say, various materials that do not impede the above characteristics can be suitably used.

  When driving the semiconductor device 40 thus formed, for example, when 1.65 V is applied as the reference voltage, the voltage generated in each thermal infrared sensor is output to the output pad 24 side in addition to the reference voltage. Is done. The output of the infrared array sensor 32 can be obtained by sequentially switching the output signal for each thermal infrared sensor by the signal processing IC chip 33 and amplifying the signal by the amplifier circuit (AMP). In the second embodiment, the signal processing IC chip 33 is formed separately from the infrared array sensor 32. However, the signal processing IC chip 33 is integrated by forming the infrared array sensor 32 on the same silicon substrate 1 at the same time. Needless to say, it can also be made. In the second embodiment, since the organic substance inside the semiconductor device 40 is removed, the infrared transmission characteristic is not changed by degassing from the organic substance or the like, and the semiconductor device 40 capable of improving the performance can be obtained. Similarly, in the case of vacuum sealing, the semiconductor device 40 can be improved without any change in the degree of vacuum due to degassing.

  In each of the above-described embodiments, the infrared array sensor 32 is exemplified as the functional device 10, but in addition, a one-axis acceleration sensor, a two-axis acceleration sensor, a three-axis acceleration sensor, a gyro sensor, a pressure sensor, a microactuator, and a microphone. It can also be used for ultrasonic sensors.

FIG. 5 is a schematic process cross-sectional view of the method for manufacturing the functional device shown in the first embodiment. FIG. 2A is a schematic plan view of the infrared array sensor as the functional device shown above, and FIG. 2B is an equivalent circuit diagram thereof. It is the thermal type infrared sensor which comprises a part of infrared array sensor shown above, (a) is the schematic plan view, (b) is the A-A 'schematic sectional drawing. It is explanatory drawing of a manufacturing method same as the above. 6 is a schematic plan view of a semiconductor device on which the infrared array sensor of Embodiment 2 is mounted. FIG. It is function explanatory drawing of a semiconductor device same as the above. It is principal process sectional drawing for demonstrating the manufacturing method of the semiconductor device carrying an infrared array sensor same as the above.

Explanation of symbols

1 Silicon substrate (substrate)
2 Functional thin film 3 Silicon wafer (wafer)
DESCRIPTION OF SYMBOLS 4 Slit 5 Cavity 6 Temporary fixing sheet 7 Dicing sheet 9 Peeling member 10 Functional device 33 IC chip for signal processing 36 Package base 37 Adhesive layer 38 Sealing adhesive layer 39 Cap 40 Semiconductor device

Claims (10)

A functional device comprising a substrate and a functional thin film formed on one surface side of the substrate, wherein a cavity for spatially separating a part of the functional thin film and the substrate is formed in the substrate. In the method, a plurality of functional devices having the functional thin film are formed on one surface side of the wafer on the wafer serving as a base of the substrate, and then separated into individual functional devices.
Affixing a dicing sheet on the other surface side of the wafer, and a sheet attaching step of directly attaching a temporary fixing sheet to the one surface side of the wafer;
After the sheet sticking step, by cutting the temporarily fixed sheet and the wafer from the temporarily fixed sheet side, a dicing step of forming a functional device chipped on the dicing sheet;
A temporary fixing sheet peeling step of peeling a plurality of temporarily fixed sheets cut by the dicing step from the plurality of functional devices, respectively;
A method for producing a functional device comprising: an organic substance removing step of removing an organic substance existing on the surface of each functional device by a dry treatment after the temporary fixing sheet peeling step.   The functional device has a slit penetrating in the thickness direction of the functional thin film and communicating with the cavity, and is present in at least one of the slit of the functional device or the inner side surface of the cavity by the organic removal step. 2. The method for producing a functional device according to claim 1, wherein organic substances are removed.   3. The temporary fixing sheet peeling step according to claim 1, wherein after the fixing member is fixed to the temporary fixing sheet, the temporary fixing sheet is peeled from the functional device together with the peeling member. The manufacturing method of the functional device as described.   The method for manufacturing a functional device according to any one of claims 1 to 3, wherein a heat-peelable pressure-sensitive adhesive sheet whose adhesive strength is reduced by heating is used as the temporary fixing sheet.   5. The functional device according to claim 4, wherein in the temporary fixing sheet peeling step, the temporary fixing sheet is peeled from the functional device by heating uniformly while applying pressure uniformly to the entire surface of the temporary fixing sheet. Manufacturing method.   Manufacturing of a semiconductor device comprising at least the functional device according to any one of claims 1 to 5, a package base on which the functional device is mounted, and a cap for sealing the package base. A method of manufacturing a semiconductor device, wherein the functional device is mounted on a package base via an adhesive layer, and then a cap is sealed to the package base via a sealing adhesive layer Method.   7. The method of manufacturing a semiconductor device according to claim 6, wherein when the package base is sealed with the cap, the inside of the package constituted by the package base and the cap is evacuated or lifted.   The method for manufacturing a semiconductor device according to claim 7, wherein an inorganic material is used for at least one of the adhesive layer and the sealing adhesive layer.   9. The method of manufacturing a semiconductor device according to claim 6, wherein organic substances in the package base and the cap are removed in advance prior to sealing of the package base.   10. The method of manufacturing a semiconductor device according to claim 9, wherein at least the package substrate is subjected to organic substance removal simultaneously with the functional device by the organic substance removal step.

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