JP2016180695A - Spectroscopic sensor and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a spectroscopic sensor capable of suppressing the reduction in sensitivity of the spectroscopic sensor due to burrs of a spectral film.SOLUTION: A spectroscopic sensor includes a spectral film 16 located on a semiconductor chip. The spectral film is located in a region of the inner side than a first length L from the outer periphery of the semiconductor chip. The spectral film 16 is removed in the region from the outer periphery of the semiconductor chip to the first length L. The first length L is longer than height H of burrs at the end of the spectral film 16.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a spectroscopic sensor and a manufacturing method thereof.

FIG. 3 is a cross-sectional view for explaining a conventional method of manufacturing a spectroscopic sensor.
As shown in FIG. 3A, a spectral film 106 is formed on a wafer 100 having a semiconductor element (not shown). The spectral film 106 is composed of 50 or more thin films, and is used for, for example, a pulse wave sensor or a spectral sensor (see, for example, Patent Documents 1 to 3).

  Next, as shown in FIG. 3B, the wafer is diced along a scribe line of the wafer 100 and separated into semiconductor chips to form a spectroscopic sensor chip.

  In the conventional method for manufacturing a spectroscopic sensor, since the wafer 100 having the spectroscopic film 106 on the scribe line is diced, a burr 107 of the spectroscopic film 106 may be generated near the outer periphery of the separated semiconductor chip. If the burr 107 is peeled off and placed on the spectroscopic sensor, the sensitivity of the spectroscopic sensor may decrease.

JP2011-209395A JP 2012-189931 A JP 2012-194438 A

  Some embodiments of the present invention relate to a spectroscopic sensor that can suppress a decrease in sensitivity of the spectroscopic sensor due to a burr of the spectroscopic film or a method for manufacturing the spectroscopic sensor.

  One aspect of the present invention includes a spectral film located on a semiconductor chip, the spectral film being located in a region inside the first length from the outer periphery of the semiconductor chip, and the first from the outer periphery of the semiconductor chip. The spectral film is removed in a region up to a length of 1, and the first length is longer than the height of a burr at the end of the spectral film.

  According to the above-described aspect of the present invention, burrs of the spectral film do not occur during dicing, so that it is possible to suppress a decrease in sensitivity of the spectral sensor due to the burrs of the spectral film.

  According to another aspect of the present invention, in the above aspect of the present invention, the semiconductor chip includes a pad, and the spectral film is removed between an outer periphery of the semiconductor chip and the pad. It is a spectroscopic sensor. Thereby, a process can be simplified.

  One embodiment of the present invention is the spectroscopic sensor according to the above embodiment of the present invention, wherein the first length is 40 μm to 120 μm (preferably 70 μm to 90 μm). As a result, it is possible to prevent the sensitivity of the spectroscopic sensor from being lowered by peeling off the burr during dicing and placing it on the spectroscopic sensor.

  One aspect of the present invention includes a step (a) of forming a spectral film on a wafer, a step (b) of removing the spectral film on the scribe line of the wafer, and a piece obtained by dicing the scribe line of the wafer. And a step (c) for forming a spectroscopic sensor.

  According to the above aspect of the present invention, since the wafer is diced after removing the spectral film on the scribe line, the spectral film is not cut by dicing. Therefore, no burr of the spectral film occurs during dicing. As a result, it is possible to prevent the sensitivity of the spectroscopic sensor from being lowered by peeling off the burr during dicing and placing it on the spectroscopic sensor.

  One embodiment of the present invention is the above embodiment of the present invention, wherein the step (a) is a step of forming a spectral film on a wafer having a pad, and the step (b) A method for manufacturing a spectroscopic sensor, comprising a step of removing a spectroscopic film on the scribe line. Thereby, a process can be simplified.

  Further, one embodiment of the present invention is the above-described one embodiment of the present invention, further including a step of forming a resist pattern on the wafer before the step (a), and the step (b) includes the resist pattern. This is a method for manufacturing a spectroscopic sensor, which is a step of removing the spectroscopic film by peeling the film with a stripping solution.

  In one embodiment of the present invention, in the above embodiment of the present invention, the cross-sectional shape of the resist pattern is a rectangle or a trapezoid, and the step (a) forms a spectral film on the resist pattern and the wafer. And a method for producing a spectroscopic sensor, characterized by being a step of generating cracks in the spectroscopic film.

  According to the above aspect of the present invention, the spectral film is formed in the step (a) and cracks are generated in the spectral film, so that the peeling solution that has passed through the cracks in the spectral film reaches the resist pattern in the step (b). By doing so, lift-off can be performed. Therefore, the spectral film can be removed by lift-off even if a resist pattern having a rectangular or trapezoidal cross-sectional shape is used.

  According to another aspect of the present invention, in the above aspect of the present invention, in the step (a), a concave portion is formed on a side surface of the resist pattern, and the spectral film in the concave portion is thinned. It is a manufacturing method of a sensor. Thereby, a crack can be easily made in the spectral film.

  In one embodiment of the present invention, in the one embodiment of the present invention, in the step (b), a side surface of the resist pattern is deformed into an overhang shape, and the spectral film on the side surface of the overhang shape is thin. This is a processing method of a spectral film. Thereby, a crack can be easily made in the spectral film.

  Further, one embodiment of the present invention is the above-described one embodiment of the present invention, in which the burr is formed at the end of the spectral film by the step (b) and the semiconductor chip separated by the step (c) is separated. An end of the spectral film is located on the inner side from the first length from the outer periphery of the semiconductor chip, and the first length is longer than the height of the burr. Thereby, it can prevent reliably that a burr | flash peels during dicing.

  One embodiment of the present invention is the method for manufacturing a spectroscopic sensor according to the above embodiment of the present invention, wherein the first length is longer than a thickness of the resist pattern. Thereby, it can prevent that a burr | flash peels during dicing.

FIGS. 4A to 4D are cross-sectional views illustrating a method for manufacturing a spectroscopic sensor according to one embodiment of the present invention. FIGS. 1A is a plan view of FIG. 1C, FIG. 1B is a cross-sectional view taken along line AA ′ shown in FIG. 1A, and FIG. 2C is an enlarged cross-sectional view of a portion 31 of FIG. (A), (B) is sectional drawing for demonstrating the manufacturing method of the conventional spectral sensor.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following description, and it will be easily understood by those skilled in the art that modes and details can be variously changed without departing from the spirit and scope of the present invention. Therefore, the present invention should not be construed as being limited to the description of the embodiments below.

  FIG. 1 is a cross-sectional view illustrating a method for manufacturing a spectroscopic sensor according to one embodiment of the present invention. 2A is a plan view of FIG. 1C, and FIG. 1C is a cross-sectional view taken along line BB ′ shown in FIG. 2B is a cross-sectional view taken along line AA ′ shown in FIG. 2A, and FIG. 2C is an enlarged cross-sectional view of a portion 31 in FIG. 2B.

  As shown in FIG. 1A, a wafer 10 is prepared. The wafer 10 is a silicon substrate on which a semiconductor element, a sensor element, an insulating film, etc. (not shown) are formed. Next, electrode pads (see the electrode pads 21 shown in FIGS. 2A and 2B) are formed on the wafer 10. This electrode pad is made of, for example, an Al film or an Al alloy film.

  Next, a passivation film 14 made of silicon nitride or the like is formed on the wafer 10 including the electrode pad 21, and an opening 14a is formed in the passivation film 14, thereby exposing the surface of the electrode pad 21 (FIG. 2A). ), (B)).

  Next, a photoresist film is applied on the electrode pad 21 and the passivation film 14, and exposed and developed to form a resist pattern 15 on the electrode pad 21 and the scribe line 22 (see FIG. 2). Since the resist pattern 15 is not a lift-off dedicated resist but a general-purpose thick novolak resist, the cross-sectional shape of the resist pattern 15 is rectangular or trapezoidal. The thickness of the resist pattern 15 is preferably 10 μm or more, for example, 10 to 20 μm. In the present embodiment, a resist pattern 15 having a trapezoidal cross-sectional shape is used.

  Next, as shown in FIG. 1B, a spectral film 16 is formed on the resist pattern 15 and the passivation film 14 and a crack (not shown) is generated in the spectral film 16 at the end of the resist pattern 15. Let

Details of the spectral film 16 are as follows.
The spectral film 16 is formed by alternately laminating thin films having a low refractive index such as silicon oxide (SiO ₂ ) and thin films having a high refractive index such as titanium oxide (TiO ₂ ) by an evaporation method. That is, a titanium oxide film is formed on the resist pattern 15 and the wafer 10 by a vapor deposition method, a silicon oxide film is formed on the titanium oxide film by a vapor deposition method, and a titanium oxide film is deposited on the silicon oxide film. The film is formed by In this way, by alternately forming the titanium oxide film and the silicon oxide film by the vapor deposition method, the spectral film 16 in which the titanium oxide film and the silicon oxide film are laminated on the resist pattern 15 and the wafer 10 is formed. . The titanium oxide film and the silicon oxide film have different film forming temperatures.

  The spectral film 16 may be a laminate of a total of two or more titanium oxide films and silicon oxide films, but is preferably a laminate of a total of 30 or more titanium oxide films and silicon oxide films. The number is preferably 50 or more.

  The temperature at which the spectral film 16 is formed may be a temperature at which the resist pattern 15 is deformed. However, the resist pattern 15 may be easily deformed by stacking two or more spectral films having different film forming temperatures. it can.

  When the spectral film 16 is formed, heat is applied to the resist pattern 15 and the resist pattern 15 is deformed by the heat. Specifically, a recess is formed on the side surface of the resist pattern 15 or the side surface of the resist pattern 15 is deformed into an overhang shape. As a result, the spectral film 16 is thinly formed on the concave portion, the spectral film 16 is thinly formed on the overhanging side surface, and defects such as cracks are generated in the spectral film 16 on the side surface of the resist pattern 15.

  Thereafter, as shown in FIGS. 1C and 2, the resist pattern 15 is removed by a stripping solution (for example, a solution containing dimethyl ether / monoethanolamine). The stripping solution reaches the resist pattern 15 through the spectral film 16 from defects such as cracks generated in the spectral film 16. Thereby, the spectral film 16 on the resist pattern 15 is removed together with the resist pattern 15. As a result, the spectral film 16 on the electrode pad 21 and the scribe line 22 is removed, and the surface of the electrode pad 21 is exposed.

  In the present embodiment, the spectral film 16 on the electrode pad 21 and the spectral film 16 on the scribe line 22 are simultaneously removed by lift-off, but the step of removing the spectral film 16 on the electrode pad 21 and the scribe line 22 are removed. The step of removing the spectral film 16 may be performed separately.

  As shown in FIGS. 2A and 2B, the spectral film 16 between the scribe line 22 and the electrode pad 21 is removed. Thereby, the spectral film 16 is removed between the outer periphery of the semiconductor chip separated after the dicing step and the electrode pad 21. By simultaneously performing the process of removing the spectral film 16 on the electrode pad 21 and the process of removing the spectral film 16 on the scribe line 22, the process can be simplified.

  In the step of FIG. 1C, the end portion of the spectral film 16 of the semiconductor chip diced along the scribe line 22 is separated from the outer periphery of the semiconductor chip by a distance L (FIG. 2C). The spectral film 16 on the scribe line 22 is removed so as to be located on the inner side (also referred to as a first length). More specifically, as shown in FIGS. 2C and 1C, burrs are formed at the end of the spectral film 16 remaining after the spectral film 16 is removed by lift-off. The spectral film 16 is removed to a region separated from the end of the scribe line 22 by a distance L (that is, H <L) longer than the burr height H. Thereby, even if the burr | flash shown in FIG.2 (C) falls, it can suppress that it protrudes outside the semiconductor chip. Such burrs are considered to occur when the spectral film 16 located on the side surface of the resist pattern 15 is removed by lift-off. Therefore, the height H of the burr is the thickness of the resist pattern 15, and the thickness of the resist pattern 15 is 10 μm or more as described above. Therefore, the distance L may be longer than the thickness of the resist pattern 10 μm, preferably 40 μm to 120 μm, and more preferably 70 μm to 90 μm.

  Thereafter, as shown in FIG. 1D, the scribe lines 22 of the wafer 10 are diced to obtain individual semiconductor chips. The semiconductor chip manufactured in this way has a spectral film 16, and the spectral film 16 is located in a region inside the distance L from the outer periphery of the semiconductor chip. In the region from the outer periphery of the semiconductor chip to the distance L, the spectral film 16 is removed. The distance L is longer than the burr height H at the end of the spectral film 16. As described above, the distance L is preferably 40 μm or more and 120 μm or less, and more preferably 70 μm or more and 90 μm or less.

  Further, the semiconductor chip has an electrode pad 21, and the spectral film 16 is removed between the outer periphery of the semiconductor chip and the electrode pad 21.

  According to the present embodiment, since the wafer 10 is diced after the spectral film 16 on the scribe line 22 is removed, the spectral film 16 is not cut by dicing. Therefore, burrs of the spectral film 16 do not occur during dicing as in the prior art. As a result, it is possible to prevent the sensitivity of the spectroscopic sensor from being lowered by peeling off the burr during dicing and placing it on the spectroscopic sensor.

  Further, in the present embodiment, a general thick film resist is used without using a resist exclusively for lift-off, and the spectral film 16 can be lifted off even if the cross-sectional shape of the resist pattern 15 is trapezoidal or rectangular. It becomes. Therefore, there are advantages in terms of cost and convenience.

  In the present embodiment, the spectral film 16 is formed by a vapor deposition method, but is not limited to the vapor deposition method, and the spectral film can also be formed by a sputtering method.

  In this embodiment, a general-purpose resist is used, but a resist dedicated to lift-off may be used. In this case, the cross-sectional shape of the resist pattern is an inverted trapezoid, which facilitates lift-off.

  In one embodiment of the present invention, when a specific B (hereinafter referred to as “B”) is formed above (or below) a specific A (hereinafter referred to as “A”) (B is formed), It is not limited to the case where B is directly formed (or B is formed) on (or below). It includes the case where B is formed (otherwise B) is formed on the upper side (or the lower side) of A through other things as long as the effects of the present invention are not inhibited.

  DESCRIPTION OF SYMBOLS 10 ... Wafer, 14 ... Passivation film | membrane, 14a ... Opening part, 15 ... Resist pattern, 16 ... Spectral film | membrane, 21 ... Electrode pad, 22 ... Scribe line.

Claims (10)

Having a spectral film located on the semiconductor chip;
The spectral film is located in a region inside the first length from the outer periphery of the semiconductor chip,
In the region from the outer periphery of the semiconductor chip to the first length, the spectral film is removed,
The spectral sensor according to claim 1, wherein the first length is longer than a height of a burr at an end of the spectral film. In claim 1,
The semiconductor chip has a pad,
The spectroscopic sensor, wherein the spectroscopic film is removed between an outer periphery of the semiconductor chip and the pad. In claim 1 or 2,
The spectroscopic sensor, wherein the first length is 40 μm or more and 120 μm or less. Forming a spectral film on the wafer (a);
Removing the spectral film on the scribe line of the wafer;
A step (c) of dicing the scribe line of the wafer into pieces;
The manufacturing method of the spectroscopic sensor characterized by including. In claim 4,
The step (a) is a step of forming a spectral film on a wafer having a pad,
The step (b) is a step of removing the spectral film on the pad and the scribe line, and a method for manufacturing a spectroscopic sensor. In claim 4 or 5,
Before the step (a), a step of forming a resist pattern on the wafer,
The step (b) is a step of removing the spectral film by peeling the resist pattern with a stripping solution, and the method for producing a spectral sensor. In claim 6,
The cross-sectional shape of the resist pattern is a rectangle or a trapezoid,
The step (a) is a step of forming a spectral film on the resist pattern and the wafer and generating cracks in the spectral film. In claim 7,
In the step (a), a concave portion is formed on a side surface of the resist pattern, and the spectral film in the concave portion is thinned. In any one of Claims 6 thru | or 8,
A burr is formed at the end of the spectral film by the step (b),
An end portion of the spectral film of the semiconductor chip singulated by the step (c) is located on the inner side from the outer circumference of the semiconductor chip with respect to the first length,
The method for manufacturing a spectroscopic sensor, wherein the first length is longer than a height of the burr. In claim 9,
The method for manufacturing a spectroscopic sensor, wherein the first length is longer than a thickness of the resist pattern.

Images