JP2000244012A - Manufacture of group iii nitride compound semiconductor element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the productivity of a semiconductor element made of a group III nitride compound semiconductor by applying and hardening sealing resin on the electrode formed side of a substrate and then dividing the substrate into individual elements. SOLUTION: A buffer layer 102 is formed on a sapphire substrate 101 and then a high carrier density n+ layer 103 and a light emitting layer 104 of a multiple quantum well structure are formed on the buffer layer 102. On the light emitting layer 104, P type layers 105, 106 are stacked. Then, a multiple thick film electrode 102 is formed by evaporation of metal on the P type layer 106 and a negative electrode 140 is formed on the n+ layer 103. Between the electrodes 120 and 140, an SiO2 protective film 130 is formed. In an element having a layer made of a group III nitride compound semiconductor formed on a substrate, a positive and a negative electrode are formed on the same side of the substrate and therefore sealing resin is only applied on one side where the positive and the negative electrode are formed. A group III nitride compound semiconductor element 100 has its electrode section resin-sealed and therefore the productivity of a flip-chip type semiconductor element having a high stability and durability can be increased.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a semiconductor device comprising a group III nitride compound semiconductor. In particular, the present invention relates to a method for manufacturing a flip chip type and a wire bonding type element.

[0002]

2. Description of the Related Art Conventionally, for example, after a flip-chip type element is formed from a group III nitride compound semiconductor, a step of connecting and sealing with an external member has been performed as follows. FIG. 6 shows the outline.

That is, as shown in FIG. 6A, a flip-chip type device 100 made of an individually divided group III nitride compound semiconductor is mounted on a substrate 10 as shown in FIG. Positive electrode 11 and negative electrode 1 formed on the element layer
2 is joined to an external member (frame) 6 on which the bumps 1 are formed by a gold ball or solder, and is sealed with a resin 3. Alternatively, as shown in FIG. 6C, the positive electrode 11 and the negative electrode 12 are connected to an indirect member (subframe) 20.
After bonding to the patterned electrodes 21 and 22 by the bump 1, the indirect member 20 is connected to the conductive adhesive 4.
To the external member (frame) 6. The electrodes 21 and 22 are bonded to the external member (frame) 6 by wires 5. Then, the element 10
0, the indirect member 20, and the external member 6 are sealed with the resin 3. The gap 33 between the element 100 and the external member (frame) 6 or the element 100 and the indirect member (subframe) 2
Since the gap 33 with respect to 0 is very narrow and may not be sufficiently filled with the resin 3 used for normal sealing, the gap 33 may be previously filled with a special resin (underfill agent).
After the sealing, a method of sealing the entire structure with a normal resin 3 has also been devised. There is also a wire bonding type element, but in this element as well, after the wafer is divided into chips, resin sealing is performed for each individual chip.

[0004]

As described above, the conventional flip-chip type and wire bonding type elements have been subjected to resin potting and heat curing treatment one by one. For this reason, there was a problem that work efficiency was poor.
Therefore, the present inventors have developed a manufacturing method for improving work efficiency, and have completed the present invention. Therefore, an object of the present invention is to improve the productivity of a method for manufacturing a semiconductor device made of a group III nitride compound semiconductor. Another object is to simplify the inspection by unifying the inspection steps performed before and after the resin sealing, respectively.

[0005]

The following means are effective in solving the above-mentioned problems. That is, the first means is:
In a method of manufacturing a semiconductor device in which a layer made of a group III nitride-based compound semiconductor is laminated on a substrate, before dividing into individual devices, a sealing resin is applied to an electrode forming side, cured, and then separated. Is divided into the elements. As these semiconductor elements, flip-chip type or wire bonding type elements can be used. The flip-chip type element is an element of a type mounted on a frame by face-down, and the wire bonding type layer is an element for connecting an electrode of the element and the frame by wire bonding by face-up.

A second means is that in a method of manufacturing a semiconductor device in which a layer made of a group III nitride compound semiconductor is laminated on a substrate, a metal is formed on each electrode surface before being divided into individual devices. A column or an electrode pad is formed, a sealing resin is applied to a portion where the metal column or the electrode pad is not formed, and after the sealing resin is cured, the device is divided into individual elements. Since the metal columns and the electrode pads are formed before the application of the sealing resin, circuit connection after the resin sealing is facilitated.
The metal pillar is a metal body formed on the electrode of the flip-chip type element, and the electrode pad is a stand for bonding formed on the electrode of the wire bonding type element. Also called.

A third means is to form a resin mask having a window, to form a metal column or an electrode pad in the window,
Thereafter, after removing the resin mask, a sealing resin is applied. In this method, a mask resin and a sealing resin for forming a metal pillar or an electrode pad are separated. The fourth means is that the sealing resin is a photosensitive resin, and after application, a window is formed at a predetermined position by photolithography, and a metal column or an electrode pad is formed in the window. . In this method, the mask resin and the sealing resin for forming the metal pillars or the electrode pads are made the same, and the mask forming step and the sealing step are made the same, thereby simplifying the steps.

A fifth means is to expose the upper surface of the metal pillar or the electrode pad by applying the sealing resin on one surface and then removing the sealing resin above the metal pillar or the electrode pad. Features. Further, the sixth means is characterized in that the metal pillar or the electrode pad is formed by plating.

[0009]

In the device in which the layer made of the group III nitride compound semiconductor is laminated on the substrate, the positive and negative electrodes are formed on the same side with respect to the substrate surface. Therefore, the sealing resin may be provided only on the side where the positive and negative electrodes are formed. Since the group III nitride-based compound semiconductor has high stability and high durability, the sealing resin only needs to be provided on the side where the electrode is formed from this surface. Instead of applying and curing this sealing resin for each individual element,
Since the application and curing of the sealing resin are performed simultaneously on a plurality of elements, the productivity is improved, and the inspection process can be performed once for one substrate. For example, in the case of a chip-type flip-chip light emitting diode (LED), a final product is obtained at the stage of division by the manufacturing method according to the present invention. Further, in the case of a chip-type wire bonding type light emitting diode (LED), it is mounted on a frame after being divided by the manufacturing method according to the present invention, and the exposed electrode pads and the lands of the frame are bonded by wires. Good. Further, in the case of a wire bonding type element, the entire structure including the frame may be sealed with a resin in order to protect the electrode pads and wires. For example, in the case of a lamp type flip chip type or wire bonding type light emitting diode (LED), a final product can be obtained simply by mounting a cap after mounting on a frame. Thus, according to the present invention, it is possible to significantly improve productivity.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described based on specific embodiments. Note that the present invention is not limited to the following embodiments.

(First Embodiment) FIG. 1 shows a flip-chip type semiconductor device 100 used in a specific embodiment of the present invention.
1 shows a schematic sectional view of FIG. The semiconductor element 100 is an example of a light emitting diode. On the sapphire substrate 101, a buffer layer 10 of aluminum nitride (AlN) having a thickness of about 200 °
2, and a high carrier concentration n ⁺ layer 103 of about 4.0 μm in thickness made of silicon (Si) doped GaN is formed thereon. Then, GaN and Ga _0.8 In _0.2 N are formed on the layer 103.
A light emitting layer 104 having a multiple quantum well structure (MQW) made of Magnesium (M
g) A p-type layer 105 made of doped Al _0.15 Ga _0.85 N and having a thickness of about 600 ° is formed. Further, on the p-type layer 105, a film made of magnesium (Mg) -doped GaN having a thickness of about 1500
Is formed.

On the p-type layer 106, a multi-thick film electrode 120 formed by metal deposition is provided, and on the n ⁺ layer 103, a negative electrode 1 is provided.
40 are formed. The multi-thick film electrode 120 is made of rhodium (Rh) or platinum having a thickness of about 0.3 μm to be joined to the p-type layer 106.
A first metal layer 111 of (Pt), a second metal layer 112 of gold (Au) having a thickness of about 1.2 μm formed on the first metal layer 111, and further formed on the second metal layer 112. This is a three-layer structure of a third metal layer 113 made of titanium (Ti) having a thickness of about 30 ° to be formed. On the other hand, the negative electrode 140 having a two-layer structure has a thickness of about
And 175Å of vanadium (V) layer 141, a high carrier concentration and an aluminum (Al) layer 142 having a thickness of about 1.8 .mu.m n ⁺ layer 103
Are sequentially laminated on a part of the exposed part.

The multiple thick film positive electrode 12 thus formed
Protective film 13 made of a SiO ₂ film between
0 is formed. The protective layer 130 is formed by etching the side surface of the light emitting layer 104, the side surface of the p-type layer 105, and the side surface and the upper surface of the p-type layer 106, which are exposed by etching from the n ⁺ layer 103 exposed to form the negative electrode 140. Part of the first metal layer 111, side surfaces of the second metal layer 112, the third metal layer 11
3 is partially covered. Protective film 1 made of SiO ₂ film
The thickness of the portion covering the third metal layer 113 is 0.5 μm.

FIG. 2 shows steps of resin sealing and individual separation (dicing) of the flip-chip type element 100 thus formed. As shown in FIG. 2A, a photosensitive thick film resist 2 is used as a mask for the flip-chip type device 100.
Form 10. The thick film resist 210 was patterned by removing the plated film growth portion 211 by photolithography. Next, a nickel (Ni) plating film 220 as a metal pillar was formed to 100 μm by electroless plating (b). Thereafter, the thick film resist 210 is removed (c).
Epoxy resin 230 was sealed to the height of nickel (Ni) plating film 220 as a sealing resin. Thereafter, solder bumps 240 were formed on the nickel (Ni) plating film 220 by screen printing (e). After adjusting the shape of the solder bumps in a reflow furnace, dicing was performed to obtain individual resin-sealed group III nitride compound semiconductor elements 100 (f).

The group III nitride-based compound semiconductor device 100 manufactured as described above can be a flip-chip type semiconductor device having high stability and durability because the electrode portion is sealed with resin. Since the group III nitride-based compound semiconductor device 100 thus manufactured can apply and cure a sealing resin to a plurality of devices at the same time, the productivity is improved,
Also, the number of inspection steps could be reduced to one. in this way,
According to the present invention, it has become possible to significantly improve productivity.

In the above-described manufacturing method according to a specific embodiment of the present invention, in the step of sealing the epoxy resin 230 as a sealing resin to the height of the nickel (Ni) plating film 220, the epoxy resin 230 is made of nickel (Ni). Ni) plating film 2
The following measures can be taken as measures to be taken when part or all of the upper surface of 20 has been covered. In either case, the thin film of the epoxy resin 230 is made of nickel (N
i) It is often used not to adhere to the upper surface of the plating film 220. (1) A washing step is provided, and only the thin film of the epoxy resin 230 on the upper surface of the nickel (Ni) plating film 220 is physically removed with a solvent. (2) Adhesive tape or the like is applied, and nickel (Ni) plating film 22
Then, only the thin film of the epoxy resin 230 on the upper surface of No. 0 is removed. (3) Only the thin film of the epoxy resin 230 on the upper surface of the nickel (Ni) plating film 220 is physically removed by pressure shaping.

In the above embodiment, the plating film is made of nickel (Ni).
But copper (Cu), gold (Au), silver (Ag), tin (Sn), etc.
In addition to using a conductive metal, it may be formed as an alloy or a stacked film thereof. Further, in the above embodiments, epoxy resin was used as the sealing resin, but polyester resin, polyimide resin, phenolic resin, polyurethane resin, silicone resin, and others,
A thermosetting resin may be used. Further, in the above-described embodiment, an example in which a solder bump is formed has been described. However, the present invention can be applied to a semiconductor element using wire bonding.

Second Embodiment The second embodiment is different from the first embodiment in that a thick-film resist 210 functioning as a mask for forming a nickel (Ni) plating film 220 as a metal pillar is replaced with a resin as a sealing resin. 230 is common. In FIG. 3, the resin 230 is made of a photosensitive polyimide resin. The photosensitive polyimide resin 230 is uniformly coated on the substrate 10 on which each layer and each electrode are formed by a spin coating method. Next, the photosensitive polyimide resin 230 is semi-cured by heating at 180 ° C. for 30 minutes. Next, a positive resist is coated and baked at 90 ° C. for 2 minutes. Next, exposure is performed using a mask pattern. The photosensitive portion of the photosensitive polyimide resin 230 is etched away using a developer. When the photosensitive polyimide resin 230 is exposed to light, it is dissolved in an alkaline solution. Acetone or IPA
For example, only the positive resist is removed. Next, the remaining photosensitive polyimide resin 230 is baked at 300 ° C. for 30 minutes to be completely cured. Thus, FIG.
As shown in FIG. 2A, a plating film growth portion 211 is formed as in FIG. Next, as shown in FIG. 3B, nickel which is a metal pillar is formed by electroless plating.
The (Ni) plating film 220 is formed. Next, as shown in FIG. 3C, the solder bumps 220 are formed by screen printing.
Is formed. Subsequent steps are the same as in the first embodiment.

Third Embodiment The third embodiment relates to a wire bonding type light emitting device. FIG. 4 shows a structure of a wire bonding type light emitting element 300. On the sapphire substrate 301, a film thickness of about 200 mm made of aluminum nitride (AlN)
Buffer layer 302 is provided, and silicon (Si)
A high carrier concentration n ⁺ layer 303 made of doped GaN and having a thickness of about 4.0 μm is formed.

On this high carrier concentration n ⁺ layer 303, a film thickness of about 200 made of non-doped In _0.03 Ga _0.97 N
A 0 ° intermediate layer 304 is formed.

The intermediate layer 304 has a thickness of about 1
An n-type cladding layer 305 made of 50 ° GaN is laminated, and a well layer 3 made of Ga _0.8 In _0.2 N having a thickness of about 30 ° is further formed.
An MQW active layer 360 having a multiple quantum well (MQW) structure in which 61 and barrier layers 362 made of GaN having a thickness of about 70 ° are alternately stacked. That is, three well layers 361
By alternately laminating the two barrier layers 362, an MQW structure having a total of five layers and two periods and a film thickness of about 230 ° is formed.

On the MQW active layer 360, a cap layer 307 made of GaN having a thickness of about 140 ° and a p-type Al
A p-type cladding layer 308 made of _0.12 Ga _0.88 N and having a thickness of about 200 ° is formed. Further, the p-type cladding layer 30
8 is made of p-type Al _0.05 Ga _0.95 N and has a thickness of about 600 °.
P-type contact layer 309 is formed.

On the p-type contact layer 309, a translucent thin film positive electrode 310 is formed by metal evaporation, and on the n ⁺ layer 303, a negative electrode 340 is formed. The translucent thin film positive electrode 310 has a thickness of about 15 to be bonded to the p-type contact layer 309.
薄膜, a thin film positive electrode first layer 311 made of cobalt (Co);
And a second layer 312 of a thin film positive electrode made of gold (Au) having a thickness of about 60 ° bonded to Co.

The thick film positive electrode (pad) 320 has a thickness of about 1
Thick film positive electrode first layer 3 made of 75 ° vanadium (V)
21, a thick positive electrode second layer 322 made of gold (Au) having a thickness of about 15000 °, and a thick positive electrode third layer 323 made of aluminum (Al) having a thickness of about 100 °. It is configured by sequentially laminating the electrodes 310 from above. The negative electrode (pad) 340 having a multilayer structure includes a vanadium (V) layer 341 having a thickness of about 175 ° and a thickness of about 1.
An aluminum (Al) layer 342 having a thickness of 8 μm is sequentially laminated on a part of the high carrier concentration n ⁺ layer 303 which is partially exposed.

Further, a protective film 330 made of a SiO ₂ film is formed on the uppermost portion.
The lowermost part on the opposite side, which corresponds to the bottom surface of No. 01, has a thickness of about 500
Reflective metal layer 350 made of 0 ° aluminum (Al)
Is formed by metal evaporation.

After a plurality of light emitting element units having the above structure are formed on a common substrate 301, the step shown in FIG. 5 is performed. That is, as shown in FIG. 5A, after uniformly applying a photosensitive resin 410 as a sealing resin, only the pad portions 320 and 340 of each electrode are exposed. And
The exposed portion is removed by etching, and a window 411 is formed on the pad portion as shown in FIG. The pads 320 and 340 exposed by the window 411 are used for wire bonding for connecting to an external frame. After sealing the surface of the substrate with the resin as described above, the substrate is separated into chips as shown in FIG.

In this embodiment, the protective film 330 need not be particularly provided. That is, the photosensitive resin 420 for sealing performs this protective action. In this embodiment, the pad 320,
Although resin sealing is performed after forming up to 340, a resin sealing step may be performed before forming the pads 320 and 340. In that case, the pads 320 and 340 are formed by the plating process in the first and second embodiments. Also in this wire bonding type light emitting element, as in the second embodiment, a mask resin and a sealing resin may be used in common, and a photosensitive resin may be used to form a mask and resin sealing.

In the above embodiment, the light emitting element is sealed. However, the present invention can be applied to any semiconductor element formed by laminating a group III nitride compound semiconductor. Further, the present invention, even other than the group III nitride compound semiconductor,
Any flip-chip type semiconductor element having high stability and durability can be applied to a flip-chip type semiconductor element made of any semiconductor.

The structure of each layer of the semiconductor element in the above embodiment is a physical or chemical structure at the time of forming each layer, and thereafter, in order to obtain stronger adhesion, or to reduce contact resistance. It goes without saying that a solid solution or a compound is formed between the layers by a physical or chemical treatment such as a heat treatment performed for the purpose of lowering the value.

In the above embodiment, the light emitting element 10
Although the light emitting layers 104 and 360 of 0 and 300 have the MQW structure, they may have an SQW structure or a homojunction structure. Further, the group III nitride compound semiconductor layer forming the device of the present invention is composed of a ternary, ternary, or binary Al _x Ga _y In _1-xy N (0
≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ x + y ≦ 1). As the p-type impurity, besides magnesium (Mg), beryllium (B
e), a group 2 element such as zinc (Zn) can be used. Further, the laminated structure of the positive electrode 140 and the negative electrode 120 and the metal used are also arbitrary. Examples of the semiconductor element to which the present invention can be applied include flip-chip type and wire bonding type light emitting diodes, laser diodes, and transistors such as FETs.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view of a semiconductor device according to a method for manufacturing a group III nitride compound semiconductor device according to a first specific example of the present invention.

FIG. 2 is a schematic diagram showing a series of procedures of resin sealing and separation according to the manufacturing method of the first embodiment.

FIG. 3 is a schematic view showing a series of steps of resin sealing and separation according to a specific manufacturing method of a second embodiment of the present invention.

FIG. 4 is a schematic cross-sectional view of a semiconductor device according to a method of manufacturing a group III nitride compound semiconductor device according to a third specific example of the present invention.

FIG. 5 is a schematic diagram showing a series of steps of resin sealing and separation according to the manufacturing method of the third embodiment.

FIG. 6 is a schematic view showing a series of conventional resin sealing procedures.

[Explanation of symbols]

Reference Signs List 100: Group III nitride compound semiconductor element (semiconductor light emitting element) 101: Sapphire substrate 102: AlN buffer layer 103: n-type GaN layer 104: light emitting layer 105: p-type AlGaN layer 106: p-type GaN layer 111 ... first thin film metal layer 112 ... second thin film metal layer 120 ... thick film positive electrode 130 ... protective film 140 ... multilayer structure negative electrode 220 ... metal column (nickel (Ni) plating film) 230 ... sealing resin (resin, Photosensitive polyimide resin) 300: light emitting element 320: thick film positive electrode (pad) 340: negative electrode (pad)

Claims (8)

[Claims] In a method of manufacturing a semiconductor device in which a layer made of a group III nitride compound semiconductor is laminated on a substrate, a sealing resin is applied to an electrode forming side before dividing into individual devices, A method for producing a group III nitride compound semiconductor device, comprising dividing an individual device after curing a sealing resin. 2. The method according to claim 1, wherein the semiconductor device is a flip-chip type device. 3. The method according to claim 1, wherein the semiconductor device is a wire bonding type device. 4. A method for manufacturing a semiconductor device in which a layer made of a group III nitride compound semiconductor is laminated on a substrate, wherein a metal column or an electrode pad is formed on each electrode surface before being divided into individual devices. A group III nitride-based compound, wherein a sealing resin is applied to a portion where the metal pillar or the electrode pad is not formed, and after the sealing resin is cured, it is divided into individual elements. A method for manufacturing a semiconductor device. 5. A method of forming a resin mask having a window, forming the metal column or the electrode pad in the window, removing the resin mask, and then applying the sealing resin. The method for producing a group III nitride-based compound semiconductor device according to claim 4, wherein: 6. The method according to claim 1, wherein the sealing resin is a photosensitive resin, and after application, a window is formed at a predetermined position by photolithography, and the metal column or the electrode pad is formed in the window. A method for manufacturing a group III nitride-based compound semiconductor device according to claim 4. 7. The method according to claim 7, wherein after applying the sealing resin on one surface, the sealing resin on the metal pillar or the electrode pad is removed to expose the upper surface of the metal pillar or the electrode pad. A method for manufacturing a group III nitride-based compound semiconductor device according to claim 4. 8. The metal column or the electrode pad is formed by plating.
3. The method for producing a group III nitride compound semiconductor device according to claim 1.