JP3427125B2 - Semiconductor device with optical lens function - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a semiconductor device with an optical lens function, and more particularly to a semiconductor device provided with an optical path of light passing through a light receiving section and a light emitting section and having a lens function in the optical path, and having a lens function. Those that can receive various types of light,
The present invention relates to one having a lens function and capable of emitting two kinds of light, and one having a lens function and having both light emitting and light receiving functions.

[0002]

2. Description of the Related Art Conventionally, optical semiconductor devices such as light receiving devices or light emitting devices have been widely used for optical communication, optical sensors, spectroscopic analysis, optical measurement and the like. Depending on applications such as optical communication and optical sensors, an optical lens that collects incident light or emitted light or collimates it is often provided in the optical path of a semiconductor device. In many cases, this optical lens is directly attached to an optical semiconductor device. For example, an optical lens for condensing light is provided between the core of the thin optical fiber and the optical semiconductor device in order to improve the optical coupling between them.

On the other hand, in order to detect the peak wavelengths of two types of light, pn junctions having different depths are formed in silicon from the light receiving surface, and a photodiode utilizing the principle that the wavelength sensitivity to incident light changes depending on the depth is used. A semiconductor color sensor in which individual layers are stacked is known. A composite optical device in which a transmissive silicon photodiode and an infrared detection element have a sandwich structure is known. On the other hand, a light emitting diode using a dome-shaped chip is also known. In this dome-shaped chip, a pn junction, which serves as a point light source, is provided in the center of a hemispherical semiconductor chip, and light emitted from the pn junction can strike the interface between the chip and the air at any angle. There is a feature that internal reflection due to the difference is reduced and light extraction efficiency is improved.

[0004]

As described above, when an optical lens that collects light is provided between the optical lens and the core of the thin optical fiber, the optical lens has only an optical function of bending light by refraction, and has a light receiving function. And does not have a light emitting function. Therefore, in multiplex communication, measurement, and sensors in which the peak wavelength of light is two types, two types of optical semiconductor devices corresponding to each wavelength must be used in addition to the optical lens.

As described above, since the semiconductor color sensor in which two photodiodes are stacked has photosensitivity to both spectra, the light output current ratio of each photodiode is measured and separated to identify the color. It is necessary, and a special circuit for that is necessary. In addition, in a composite optical device that has a sandwich structure of a transmissive silicon photodiode and an infrared detection element, since the function as a lens is not added to the transmissive silicon photodiode, incident light is not collected and the infrared detection element surface The incident energy density is low, and there is a limit to increase the photoelectric conversion efficiency. The light emitting diode using the dome-shaped chip does not have an optical path for transmitting other incident light, and therefore only functions as a light emitting diode.

An object of the present invention is to provide a semiconductor device which enables a new application area in which an optical system and an electronic system are fused, a semiconductor device having a function of receiving and emitting light and a lens function for external light, and two kinds of light. Providing a semiconductor device such as a compound semiconductor device having a light receiving function or a light emitting function and a lens function, a compound semiconductor device having a light receiving function, a light emitting function, and a lens function, optical communication, optical information processing, and spectroscopy To provide a semiconductor device useful for analysis, an optical sensor, etc., to provide a semiconductor device capable of expanding a spectral sensitivity wavelength range and an emission spectrum, and the like.

[0007]

Means for Solving the Problems A semiconductor device with lens function according to claim 1, Oite a semiconductor device with a light receiving unit for photoelectrically converting incident light, composed of a part of a light transmissive semiconductor light receiving portions Light is received by this light-permeable semiconductor.
An optical path is formed for transmitting light that has passed through the optical path or light that is directed toward the light receiving section, and a lens function is added to a part of this optical path. As the light receiving section, various photodiode configurations can be appropriately adopted. The lens that obtains the lens function may be spherical, hemispherical, rod-shaped, cylinder-shaped, round-drum-shaped, convex, or the like, as long as it can convert the traveling direction of light into a desired direction by refraction.

[0008] In this light permeable semiconductor, transmitted through the light-receiving unit
Since an optical path for transmitting the incident light or the light directed to the light receiving portion is formed and a lens function is added to a part of this optical path, a part of the incident light is photoelectrically converted by the light receiving portion and Another part of the light can be transmitted through the light receiving portion and the optical path, and can be condensed or collimated by the lens function and emitted to the outside. Then, the transmitted light can be efficiently detected by another light receiving device with high sensitivity. Also, while a part of the incident light is photoelectrically converted by the light receiving part, the light emitted by another light emitting device is transmitted through the optical path and is condensed by the lens function or collimated and emitted to the outside. be able to.

As described above, by the light transmissive semiconductor
Since a lens function is obtained by effectively utilizing a part of the formed optical path , the size can be reduced, the configuration can be simplified, the semiconductor material can be saved, and the manufacturing cost can be reduced. Moreover, by combining with an external light receiving device, two types of incident light can be independently photoelectrically converted, and light having an increased energy density can be efficiently and highly photoelectrically converted by the light receiving device.
Further, by combining with an external light emitting device, it becomes possible to receive part of the incident light, perform photoelectric conversion, and emit the emitted light.

According to another aspect of the semiconductor device with a lens function of the present invention, in the semiconductor device having a light emitting portion for converting electric energy into light, the light emitting portion is made of a part of a light transmissive semiconductor , and the light transmissive is possible. Is it a light emitting part in a semiconductor
An optical path for transmitting the light emitted from the optical path is formed, and a lens function is added to a part of the optical path. As the light emitting portion, various light emitting diode configurations can be appropriately adopted, and the lens having the lens function is the same as that of the first aspect. Since the light emitting portion is provided, the emitted light can be emitted. An optical path for transmitting the light emitted from the light emitting part is formed in a light transmissive semiconductor, and a lens function is provided in a part of this optical path. Therefore, the light emitted by an external light emitting device is transmitted through the optical path and has a lens function. It is possible to condense light into parallel light and emit it to the outside. Further, it becomes possible to receive the transmitted light of the incident light transmitted through the light emitting portion and the optical path by an external light receiving device and perform photoelectric conversion.

As described above, the light transmissive semiconductor is used.
Since a lens function is obtained by effectively utilizing a part of the formed optical path , the size can be reduced, the configuration can be simplified, the semiconductor material can be saved, and the manufacturing cost can be reduced. Moreover, by combining with another light emitting device, it becomes possible to independently generate and emit two types of light. Further, by combining with another light receiving device, it becomes possible to supply light having an increased energy density by the lens function to the light receiving device and perform photoelectric conversion with high sensitivity.

According to a third aspect of the present invention, in the semiconductor device with a lens function according to the first aspect of the invention, a second light receiving portion for photoelectrically converting incident light is integrally incorporated, and the incident light transmitted through the optical path is transmitted through the second light receiving portion. It is characterized in that it is configured to receive light. As the second light receiving section, various photodiode configurations can be appropriately adopted as in the case of the light receiving section. The lens function is the same as in claim 1. However, since light having a short wavelength is easily absorbed in the semiconductor, the wavelength of light received by the second light receiving unit is set to be larger than the wavelength of light received by the light receiving unit. Since the light receiving section and the second light receiving section can independently receive two types of incident light having different wavelengths and perform photoelectric conversion, a semiconductor device useful in the fields of optical communication, optical information processing, spectroscopic analysis, optical sensor, and the like. In addition, the lens function can enhance the light receiving sensitivity of the second light receiving unit.

According to a fourth aspect of the present invention, in the semiconductor device with a lens function according to the first aspect of the invention, a light emitting portion for converting electric energy into light is integrated, and light emitted from the light emitting portion passes through the optical path. It is characterized in that the light is emitted. As the light emitting portion, various light emitting diode configurations can be appropriately adopted. The lens function is the same as in claim 1. However, the light emitted from the light emitting portion is light having a wavelength that can be transmitted through the optical path. Incident light can be photoelectrically converted by the light receiving unit, and light emitted from the light emitting unit can be transmitted through the optical path to be condensed or collimated and emitted to the outside. In this case, since light having a wavelength longer than the wavelength of light received by the light receiving section may be generated from the light emitting section, for example, it is possible to receive and emit light having different wavelengths. An applicable light emitting device can be provided, and a semiconductor device for an optical sensor having both a light receiving function and a light emitting function can be provided.

According to a fifth aspect of the present invention, in the semiconductor device with a lens function according to the second aspect of the present invention, a second light emitting portion for converting electric energy into light is integrated, and the light emitted from the second light emitting portion is in the optical path. It is characterized in that it is configured to be transmitted through and emitted. As the second light emitting portion, various light emitting diode configurations can be appropriately adopted.
The lens function is the same as in claim 1. However, the light emitted from the second light emitting portion is light having a wavelength that can be transmitted through the optical path. The light emitting unit can emit and emit one kind of light,
The second light emitting unit can emit and emit different kinds of light. Since the light emitting section and the second light emitting section can independently emit two types of light having different wavelengths, it is possible to provide a semiconductor device useful in the fields of optical communication, optical information processing, spectroscopic analysis, optical sensors, and the like.

According to a sixth aspect of the present invention, in the semiconductor device with a lens function according to the second aspect of the invention, a light receiving section for photoelectrically converting incident light is integrally incorporated, and the incident light transmitted through the optical path is received by the light receiving section. It is characterized by being configured. As the light receiving section, various photodiode configurations can be appropriately adopted. The lens function is the same as in claim 1. The light emitted by the light emitting unit can be emitted to the outside, and the incident light that has passed through the optical path of the incident light can be received by the light receiving unit and photoelectrically converted. Similarly to the third aspect, it is possible to provide a light emitting device to which bidirectional optical communication can be applied. Further, it is possible to provide a semiconductor device for an optical sensor having both a light receiving function and a light emitting function.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Various embodiments of the present invention will be described below with reference to the drawings. Embodiment 1: "Silicon photodiode with hemispherical lens" The semiconductor device with an optical lens function according to this embodiment is a silicon photodiode PD1 with a hemispherical lens having the structure shown in FIGS. The structure of PD1 and its manufacturing method are explained.

In this silicon photodiode PD1 with a hemispherical lens, the radius is 0.2 to 2.0 mm in the central portion on the surface side of the silicon substrate 1 made of p-type silicon crystal having a thickness of about 2.0 to 4.0 mm and capable of transmitting light. A hemispherical lens 2 of a certain degree is formed, and an n ⁺ diffusion layer 3 in which an n-type impurity such as phosphorus is diffused is formed on the surface of the hemispherical lens 2 to form a hemispherical n ⁺ p junction 4 (this n ⁺ p-junction 4 and its vicinity correspond to a light receiving portion PA that receives and photoelectrically converts incident light), is insulated from the silicon substrate 1 via the insulating film 5 of SiO ₂ , and is an n ⁺ diffusion layer. A cathode 6 electrically connected to 3 is formed, and a SiO ₂ antireflection film 7 having an appropriate thickness is formed on the surface of the hemispherical lens 2.

The silicon substrate 1 is formed with an optical path 8 which penetrates the n ⁺ p junction 4 and transmits incident light from the upper side to the lower side or in the opposite direction, and the hemispherical lens 2 is formed in the optical path 8. On the back surface side of the substrate 1, there is a light transmission window 9 for transmitting the light passing through the optical path 8 from the upper side to the lower side or in the opposite direction, which is a circular light transmission window 9 concentric with the optical axis of the hemispherical lens 2. An antireflection film 10 of SiO ₂ is formed on the light transmitting window 9 and an anode 11 electrically connected to the silicon substrate 1 is formed.

When manufacturing this silicon photodiode PD1 with a hemispherical lens, the front surface and the back surface of the p-type silicon crystal silicon substrate 1 are covered with a silicon oxide film, and then the front surface is subjected to an etching treatment so as to be projected upward. To form the hemispherical lens 2. After the surface on the side where the lens 2 is present is covered with a silicon oxide film, the hemispherical surface and a part of the silicon oxide film around it are removed by etching treatment, and the hemispherical surface and its surroundings are exposed to phosphorus by a known technique. The n-type impurity is diffused to form an n ⁺ diffusion layer 3 to form a dome-shaped n ⁺ p junction 4.

After the silicon oxide film is completely removed by etching, the surface of the silicon substrate 1, the entire surface of the lens 2 and the back surface of the silicon substrate 1 are again coated with the silicon oxide film by a method such as CVD. By a known photo-etching technique, the silicon oxide film 5 is left on the end surface of the n ⁺ diffusion layer 3 and its periphery, and the circular silicon oxide film 10 concentric with the optical axis of the lens 2 is left on the back surface of the silicon substrate 1, The cathode 6 and the anode 11 are each formed by an evaporation method as shown in FIG.
It is provided so as to make ohmic contact with the p-type surface. On the surface of the hemispherical lens 2, an antireflection film 7 of SiO _{2 having} an appropriate film thickness is formed by a known method such as CVD. In the light transmission window 9, the circular silicon oxide film 10 serves as an antireflection film. Incidentally, these antireflection films may be formed to have an appropriate film thickness by using an appropriate material other than SiO ₂ depending on the transmitted light. The silicon photodiode PD1 chip thus manufactured is attached to an appropriate supporting member, and the anode 11 and the cathode 6 are connected to an external electric circuit by wire bonding or the like.

Silicon has a characteristic that it absorbs light having a wavelength of about 1.1 μm or less at room temperature, but does not absorb light having a wavelength of more than that and transmits it. Therefore, the incident light having a wavelength of 1.1 μm or more that is incident from the surface side of the hemispherical lens 2 is refracted by the hemispherical lens 2, passes through the light transmitting window 9 and travels downward to be condensed on the optical axis. If another photodiode that can absorb the light of this wavelength is provided at this position, the energy density of the incident light is increased, and photoelectric conversion can be performed with high efficiency. It is also possible to introduce light at the tip. Silicon photodiode with filtered light of wavelength less than 1.1 μm
The light absorbed in the n ⁺ p junction 4 of PD1 and its vicinity is photoelectrically converted, and can be taken out as an electric signal or electric energy from the anode 11 and the cathode 6.

On the other hand, the light transmission window 9 on the back surface of the silicon substrate 1
Light having a wavelength of 1.1 μm or more, which is incident from below, is refracted by the hemispherical lens 2, spreads out from the lens surface, and is emitted. As described above, since the light transmission window 9 is provided, the function of a photodiode that performs photoelectric conversion according to the wavelength of light and the light passing through the optical path 26 from above to below or from below to above can be collected or diffused. Both functions of the optical lens can be obtained. Moreover, since the lens function is obtained by effectively utilizing the semiconductor that constitutes at least a part of the light receiving portion, the size can be reduced, the configuration can be simplified, the semiconductor material can be saved, and the manufacturing cost can be reduced. Moreover, it is possible to realize a semiconductor device useful in the fields of optical communication, optical information processing, spectroscopic analysis, optical sensors, and the like.

In the above embodiment, the hemispherical lens 2
Instead of forming the n ⁺ p junction 4 in the surface portion of the form in a planar shape to a circle the n ⁺ p junction in the upper vicinity of the lower surface of the light transmission window 9, n ⁺ diffusion layer, p-type silicon substrate and the ohmic A ring-shaped cathode and an anode may be provided so as to be in contact with each other. In this case, n is set at the focus position where the received incident light is collected.
^{If the +} p junction is provided, the energy density of incident light can be increased, and photoelectric conversion can be surely performed even if the n ⁺ p junction is formed to be small. In addition, by replacing the n ^{+ -type} semiconductor with a p ^{+ -type} semiconductor, replacing the silicon substrate 1 of p-type silicon crystal with an n-type semiconductor crystal substrate, or replacing the silicon semiconductor crystal with another semiconductor crystal, Of course, a photodiode having a similar structure may be used. The shape of the hemispherical lens is merely an example, and the lens may be spherical, hemispherical, rod-shaped, cylinder-shaped, round drum-shaped,
It may be a convex shape or the like as long as it can convert the traveling direction of light into a target direction by refraction.

Embodiment 2: "Silicon photodiode with hemispherical lens" A semiconductor device with an optical lens function according to this embodiment is a silicon photodiode PD2 with a hemispherical lens shown in FIGS. diode
PD2 is almost the same as the silicon photodiode PD1 of the first embodiment. Therefore, in brief description, a hemispherical lens 22 convex upward is formed on the surface of a silicon substrate 21 made of p-type silicon crystal. , Silicon substrate 21
An antireflection film 23 of SiO ₂ is formed on the surface of the lens 22. An n ⁺ diffusion layer 24 and an n ⁺ p junction 2 in which an n-type impurity such as phosphorus is diffused in the center of the back surface of the silicon substrate 21.
5 (this n ⁺ p junction 25 and its vicinity correspond to the light receiving portion PA that photoelectrically converts incident light) are formed in a planar shape.

An optical path 26 is formed in the silicon substrate 21 to penetrate the n ⁺ p junction 24 and transmit incident light from the upper side to the lower side or in the opposite direction, and the hemispherical lens 22 is formed in the optical path 26. On the rear surface side of the substrate 21, there is provided a light transmission window 27 for transmitting the light transmitted through the optical path 26 from the upper side to the lower side or in the opposite direction, which is a circular light transmission window 27 concentric with the optical axis of the hemispherical lens 22. An antireflection film 28 of SiO ₂ is formed on the light transmitting window 27.
An insulating film 28 of SiO ₂ is formed on a portion of the back surface of the silicon substrate 21 around the light transmission window 27.
The anode 29 and the cathode 30 formed on the back surface side of 1 are respectively p-type silicon substrate 21 and n ⁺ on the same plane as shown in the figure.
It is electrically connected to the diffusion layer 24.

Light incident from the hemispherical lens 22 side passes through the optical path 26 and is condensed toward the lens focus on the n ⁺ p junction 24 side. Therefore, the light received by the n ⁺ p junction 24 is condensed and the energy density is increased, and the effect of increasing the photoelectric conversion efficiency is obtained. The manufacturing method of the photodiode PD2 and other functions and effects are almost the same as those of the first embodiment. The lens may be spherical, hemispherical, rod-shaped, cylinder-shaped, round-drum-shaped, convex-shaped or the like as long as it can convert the traveling direction of light into a desired direction by refraction.

Embodiment 3: “Light emitting diode with hemispherical lens” (see FIGS. 5 and 6) The semiconductor device with an optical lens function according to the present embodiment is a light emitting diode with a hemispherical lens shown in FIGS. 5 and 6.
The light emitting diode LED1 is the LED 1 and the hemispherical lens 4 is the same as the silicon photodiode PD2 of the second embodiment.
The method for manufacturing the light emitting diode LED1 and the structure thereof will be described. Thickness of n-type GaAlAs with Al (aluminum) mixed crystal ratio of 0.10 to 0.15
A 0.5 mm single crystal substrate 41 is prepared, and a mixed crystal ratio of the GaAs layer 43 made of an n-type GaAs crystal of about 0.01 mm and Al is 0.10 to 0.15 on the back surface of the crystal substrate 41. And a GaAlAs layer 44 made of GaAlAs crystals of the same shape are sequentially grown by a known liquid phase epitaxial growth method.

Next, a silicon nitride film (not shown) is deposited, and a circular light transmission window 45 (the center of the light transmission window 45 is substantially aligned with the optical axis of the hemispherical lens 42) is deposited on the silicon nitride film. A circular p-type diffusion layer 46 by penetrating the n-type GaAlAs layer 44 and thermally diffusing Zn to the n-type GaAs layer 43 using the silicon nitride film as a mask. To form. As a result, a circular pn junction 47 of GaAs (this pn junction 47 and its vicinity correspond to the light emitting portion PB for converting electric energy into light) is formed. After removing the oxide film on the epitaxial growth surface and depositing a silicon nitride insulating film 48 which also functions as an antireflection film,
The surface of the p-type diffusion layer 46 is removed in a ring shape by etching to expose the surface of the GaAlAs layer 44, and an Au-Zn alloy film is vapor-deposited to form an anode 49. Further, the silicon nitride insulating film on the n-type GaAlAs layer 44 and the Au—Zn alloy film are removed by etching, and the Au—Ge—Ni alloy film is vapor-deposited to form the cathode 50. Anode 4
9 and the cathode 50 are formed in a ring shape.

Next, the entire outer surface is masked and the surface side of the crystal substrate 41 is etched to form a circular and p-type diffusion layer 46.
A dome-shaped hemispherical lens 42 having a radius of about 0.10 to 0.25 mm and concentric with is formed as shown in the drawing, and the surface of the hemispherical lens 42 and the surrounding surface are reflected from an appropriate material (for example, SiO ₂ ). The prevention film 57 is formed. In the crystal substrate 41,
An optical path 51 for transmitting light is formed through the circular pn junction 47, and a hemispherical lens 42 is formed in the optical path 51. LED chip 40 manufactured as described above
A silicon submount 5 having a circular through hole 53.
2. Stick on 2. Square silicon submount 52
Is entirely covered with a silicon oxide insulating film 54, and the surface of the Ni-A is ring-shaped and extends from the through hole 53 to the rear surface.
On the front surface side of the anode connection film 55 made of u and the silicon submount 52, a similar cathode connection film 56 surrounding the circumference of the ring is formed at regular intervals.

As shown in the figure, the LED chip 40 is fixed on the silicon submount 52 with the centers of the hemispherical lens 42 and the through hole 53 aligned, and the anode 49 and the anode connecting film 55, and the cathode 50 and the cathode connecting film 56. Each is electrically connected and fixed with a suitable solder material. When the chip of the light emitting diode LED1 with a hemispherical lens with the silicon submount 52 is attached to a supporting member (not shown) and a forward current is passed between the electrodes 49 and 50, light is emitted vertically from the pn junction 47. The light that passes through the optical path 51 and the hemispherical lens 42 has little internal reflection and spreads and is emitted.

The peak of this emission wavelength is about 0.8 μm, and the GaAlAs crystal substrate 41 allows light of this wavelength to pass through with almost no absorption. Basic absorption edge of GaAs (wavelength at room temperature
When incident light from the outside having a wavelength longer than 0.9 μm enters from the hemispherical lens 42 side, the light is transmitted through the optical path 51 in the central portion of the LED chip 40, is condensed, passes through the light transmission window 45, and is focused downward. tie. Therefore, by providing an optical fiber or a light receiving element for receiving this light at this position, it becomes possible to receive an optical signal with high energy density.
Further, since the light transmission window 45 and the through hole 53 are provided,
A part of the incident light from above can be transmitted to the through hole 53, and the incident light from below can be transmitted to the hemispherical lens 42. Similar to the first embodiment, the size can be reduced, the configuration can be simplified, the semiconductor material can be saved, the manufacturing cost can be reduced, and it is useful in the fields of optical communication, optical information processing, spectroscopic analysis, optical sensor, and the like. It is possible to realize various semiconductor devices.

In this embodiment, it is possible to manufacture a light emitting diode having a lens shape similar to that shown in FIGS. 5 and 6 by using another semiconductor crystal used as a light emitting diode such as GaP instead of the crystal substrate 41. . Furthermore, pn
The joint 47 may be formed in a dome shape along the surface of the hemispherical lens 42. In addition, it is also possible to make a photodiode by appropriately changing design parameters with the same structure as in FIGS. 5 and 6 to obtain a light receiving device having a lens function and a filter function. The lens may be spherical, hemispherical, rod-shaped, cylinder-shaped, round-drum-shaped, convex-shaped or the like as long as it can convert the traveling direction of light into a desired direction by refraction.

Embodiment 4: "Spherical light emitting diode" (see FIGS. 7 to 9) A semiconductor device with an optical lens function according to this embodiment is a spherical light emitting diode LED2 shown in FIGS.
In this light emitting diode LED2, an n-type GaP formed on one side of a p-type GaP crystal 61, which is a light-transmittable semiconductor, is used.
A crystal layer 62 (which is also a light transmissive semiconductor) and a p-type GaP crystal 6 are formed on the spherical lens 60 as a whole.
1 and the n-type GaP crystal layer 62, a pn junction 63 (this pn junction 6
3 and its vicinity correspond to a light emitting portion PB for converting electric energy into light, and the anode 6 is provided on both apexes of the spherical lens 60 located on both sides of the pn junction 63.
4 and the cathode 65 are formed, and the axis of the spherical lens 60 connecting the anode 64 and the cathode 65 is orthogonal to the pn junction 63. This spherical lens 60 is used for incident light B1, B2, B3, B4 in various directions.
On the other hand, there is formed an optical path 66 having an optical lens function, which is an optical path 66 for transmitting light which passes through the light emitting portion including the pn junction 63 and its vicinity.

When the spherical light emitting diode LED2 is manufactured, an n-type GaP crystal layer 62 doped with N (nitrogen) is formed on a p-type GaP crystal substrate 61 by a liquid phase epitaxial growth method or the like, and then ohmic contacts are formed on both sides. Contact A
A plurality of sets of anodes 64 and cathodes 65 containing u as a main component are provided, and these are cut into a rectangular parallelepiped shape.
Roughly process to a spherical shape of 0.3 to 0.6 mm. Further, the spherical surface is mirror-finished by a chemical mechanical polishing method.

When the anode 64 and the cathode 65 are fixed to an appropriate supporting member (not shown), the anode 64 and the cathode 65 are connected to external electric circuits, respectively, and a forward current is applied to the pn junction 63, a pn junction is formed.
Yellow-green light having a peak wavelength of 0.56 μm is radiated in all directions from the vicinity including the junction 63. Although this itself has a function as a light emitting diode (LED), it can function as an optical spherical lens for light having a wavelength that is not absorbed by the GaP crystal forming the spherical lens 60. That is, like any one of the incident lights B1, B2, B3, B4, when the light is made incident, the light is refracted by the spherical lens 60, and the incident parallel light is condensed at the focal point on the optical axis of the spherical lens 60. To do. If a light source that generates light having a wavelength that can pass through the spherical lens 60 is placed at the focal point, the light that has passed through the light emitting diode LED2 travels as parallel light. Further, as in the case of the first embodiment, it can be downsized, the configuration can be simplified, the semiconductor material can be saved, the manufacturing cost can be reduced, and the fields such as optical communication, optical information processing, spectroscopic analysis, and optical sensor can be achieved. In this way, a useful semiconductor device can be realized.

It is possible to make a spherical lens 60 by using another semiconductor crystal that can be used for a light emitting diode instead of the GaP crystal, and have a light emitting function and a lens function for light of a wavelength longer than that wavelength. Is. Incidentally, FIG.
~ The spherical GaP light emitting diode LED2 in Fig. 9 is 0.19 ~ 0.55
It can also be used as a photodiode that absorbs light with a wavelength of μm. In this case, the spectrum of 0.55 μm or less is cut, and the light of the spectrum of more than 0.55 μm is condensed by the spherical lens 60. The lens may be spherical, hemispherical, rod-shaped, cylinder-shaped, round-drum-shaped, convex-shaped or the like as long as it can convert the traveling direction of light into a desired direction by refraction.

Embodiment 5: "Composite Photodiode"
(See FIGS. 10 and 11) A semiconductor device with an optical lens function according to the present embodiment is a composite photodiode PD3 shown in FIGS.
In this composite photodiode PD3, the silicon photodiode PD1 of the first embodiment (FIGS. 1 and 2) is
It is a composite of the InGaAs / InP photodiode PD4, which is superposed on the chip. Since the structure and manufacturing method of the silicon photodiode PD1 are the same as those described in the first embodiment, the same elements are designated by the same reference numerals and the description thereof will be omitted, and the manufacturing method and the structure of the InGaAs / InP photodiode PD4 will be described. To do.

On the crystal substrate 71 made of n ⁺ -InP crystal, the buffer layer 72 made of n-InP crystal and the mixed crystal ratio of In are 0.
The light absorption layer 73 made of n-InGaAs crystal 58, n ⁺ -I
The window layer 74 made of nP crystal is sequentially grown by the well-known MOCVD method as shown in the figure. After depositing the silicon nitride film 75 on the surface of the window layer 74, a silicon nitride film (not shown) corresponding to the central portion of the crystal substrate 71 to be cut into chips in a later step (similar to the silicon nitride film 75) The diameter of film is 0.08 to 0.30mm by photo etching.
A circular window is opened, and Zn, which is a p-type impurity, is thermally diffused by using the silicon nitride film 75 around the window as a mask to form an n ⁺ -InP window layer 74 and an n-InGaAs light absorption layer 73. p
The diffusion layer 76 is formed, and the pn junction 77 is formed in the light absorption layer 73.

After removing the mask of the silicon nitride film, a silicon nitride film 75 having a predetermined thickness is again deposited on the surfaces of the p-type diffusion layer 76 and the window layer 74 by CVD to cover the outer surface of the light transmitting window 9. A protective film 75b that protects the antireflection film 75a and the pn junction 77 is formed. Then, in order to provide the anode 78 which makes ohmic contact with the p-type diffusion layer 76, the silicon nitride film 75 on the circular p-type diffusion layer 76 is photo-etched.
Open a ring-shaped window on the anode and deposit an Au-Zn alloy film on the anode 7.
8 is formed. Further, the vapor deposition film of Au—Zn alloy on the antireflection film 75a in contact with the p-type diffusion layer 76 is removed to expose the light receiving surface. A known lift-off method can be applied to remove the vapor-deposited film of the Au-Zn alloy. On the back surface of the crystal substrate 71, an Au-Ge-Ni alloy film is vapor-deposited on the entire surface to form a cathode 79 in order to provide a cathode 79 in ohmic contact therewith. This InGaAs / InP photodiode
PD4 absorbs and photoelectrically converts light having a wavelength of 0.90 to 1.65 μm at room temperature.

On the upper surface of the InGaAs / InP photodiode PD4 thus formed, the chip of the silicon photodiode PD1 described in the first embodiment is aligned with the optical axis of the hemispherical lens 2 at the center of the p-type diffusion layer 76 as shown in the figure. Stack as shown in FIG.
When the anode 78 of the As / InP photodiode PD4 is fixed and electrically connected by a solder material (not shown) or the like, a chip of the composite photodiode PD3 is formed. Although not shown, the chip of the composite photodiode PD3 is mounted on a supporting member such as a suitable case, and the common anode 11,
78, the cathodes of both photodiodes PD1 and PD4 6,79
A 3-terminal composite photodiode PD3 having and is completed.

The silicon photodiode PD1 of the composite photodiode PD3 has a sensitivity on the short wavelength side which varies depending on the position from the surface of the pn junction 4, but is about 0.
The InGaAs / InP photodiode PD4 absorbs light of wavelengths of 32 to 1.10 μm, and the InGaAs / InP photodiode PD4 absorbs light of wavelengths of 0.90 to 1.65 μm.
It is possible to detect light having a wavelength of m. Like this one
With one device, high photosensitivity and wide detection wavelength range can be obtained. However, the anode 11 can be fixed to the surface of the anode 78 via an insulating film. In this case, the photodiodes PD1 and PD4 have independent light receiving functions, and two types of incident light are independently photoelectrically converted. It can be converted. The lens may be spherical, hemispherical, rod-shaped, cylinder-shaped, round-drum-shaped, convex-shaped, or the like as long as it can convert the traveling direction of light into a desired direction by refraction. Others As in the first embodiment, the size can be reduced, the configuration can be simplified, the semiconductor material can be saved, the manufacturing cost can be reduced, and in the fields of optical communication, optical information processing, spectroscopic analysis, optical sensor, etc. A useful semiconductor device can be realized.

Here, instead of the silicon photodiode PD1 of the first embodiment, the silicon photodiode PD2 of the second embodiment may be used to form a composite photodiode. In this case, InGaAs / InP photodiode PD
The anode 78 of 4 is the anode 2 of the silicon photodiode PD2.
9 is provided so as to be in contact with the cathode 9 of the silicon photodiode PD2 independently on the same plane.

Also, InGaAs / InP photodiode PD4
Instead of the above, a light receiving device made of another semiconductor capable of absorbing light having a wavelength transmitted through the silicon photodiode PD1 may be combined. For example, combine a photodiode such as a germanium photodiode, Ga-In-As-Sb / Ga-Al-As-Sb heterostructure photodiode, or In-As-Sb-P / InAs heterostructure photodiode with a silicon photodiode. Good. These photodiodes are
Sensitivity cutoff of 10%, 1.55μm and 2.4μ, respectively
It has a photosensitivity up to m and 3.8 μm, and a wide range of photosensitivity characteristics can be obtained by combining it with a silicon photodiode.

Embodiment 6: "Composite light emitting diode"
(See FIGS. 12 and 13) The semiconductor device with an optical lens function according to the present embodiment is the composite light emitting diode LED3 shown in FIGS. 12 and 13, and the composite light emitting diode LED3 is the same as that of the fourth embodiment.
GaP light emitting diode LED2 explained in (Figs. 7-9)
Is combined with the GaAlAs infrared light-emitting diode LED4.
The same elements as those in FIG.

The manufacturing method and structure of the GaAlAs infrared light emitting diode LED4 will be described.
The LED 4 can be manufactured by a known technique using the n-type GaAs crystal substrate 81. First, n was formed on a crystal substrate 81 made of n ⁺ -GaAs crystal by a liquid phase epitaxial method.
-Type cladding layer 82 made of GaAlAs crystals with an Al mixed crystal ratio of 0.3, p-type active layer 83 made of GaAlAs crystals with an Al mixed crystal ratio of 0.03, n-type GaAlAs crystals having an Al mixed crystal ratio of 0.15 A cap layer 84 made of is sequentially laminated as shown by epitaxial growth.

As described in the fifth embodiment, a circular window is opened in the center of a silicon nitride film (not shown) (a film substantially corresponding to the silicon nitride film 87) formed on the surface of the cap layer 84. By using the silicon nitride film around the window as a mask to diffuse Zn into the center, a diameter of about 0.20 m
A circular p-type diffusion layer 85 of m is formed so as to penetrate the cap layer 84 and contact the active layer 83, and a circular pn junction 86 is formed.
(This pn junction 86 and its vicinity correspond to a light emitting portion that electro-electrically converts electric energy into light). Next, after removing the silicon nitride film, a silicon nitride film 87 is formed again on the entire surfaces of the p-type diffusion layer 85 and the cap layer 84, and an anode 88 that makes a ring-like contact is provided on the surface of the p-type diffusion layer 85. Therefore, the silicon nitride film 87 is removed in a ring shape, Au-Zn-Au is vapor-deposited, the vapor deposition layer on the surface side of the p-type diffusion layer 85 and the silicon nitride film 87 are removed by etching, and the light transmission window 89 and the anode are formed. 88 is formed.

Next, an insulating layer 90 made of polyimide resin having a predetermined thickness is formed on the surfaces of the light transmitting window 89 and the anode 88, Au-Ge-Ni is vapor-deposited on the surface of the insulating layer 90, and the vapor deposition is performed. By photo-etching with the layer masked in a predetermined pattern, an opening window 91 (which corresponds to the upper side of the light transmission window 89) for housing the lower end of the light emitting diode LED2 is formed in the insulating layer 90. At the same time, an anode extraction electrode 92 and a cathode extraction electrode 93 as shown in FIG. 13 are formed.
Next, Au-Ge-Ni is vapor-deposited on the back surface side of the crystal substrate 81 to form the cathode 94.

Opening window 91 of this infrared light emitting diode LED4
Then, the lower end of the light emitting diode LED2 described in the fourth embodiment is fitted and fixed with the transparent synthetic resin 95. Then, the anode 64 and the cathode 65 of the light emitting diode LED2 are connected to the silver paste 96,
97, an anode extraction electrode 92 and a cathode extraction electrode 9 respectively.
3 is electrically glued and connected. The infrared light emitting diode
The anode 88 and the cathode 94 of the LED 4 are respectively connected to an external electric circuit, and the anode extraction electrode 92 and the cathode extraction electrode 93 of the light emitting diode LED2 are similarly connected to the external electric circuit. The composite light emitting diode LED3 has, for example, a cathode 94
Is fixed to an appropriate case or a supporting member. When both the light emitting diodes LED2 and LED4 are simultaneously operated and used, the anode 88 may be connected to the anode extraction electrode 92 to form a common anode.

When a forward current is passed between the anode 88 and the cathode 94 of the infrared light emitting diode LED4, infrared light having a peak wavelength of about 0.85 μm is generated from the active layer 83 having the pn junction 86, and the infrared light is transmitted through the light transmitting window 89. The light passes through the optical path 66 in the spherical lens 60 of the light emitting diode LED2 and is emitted to the outside. If the light transmitting window 89 of the infrared light emitting diode LED4 is made small and brought close to the point light source and is arranged at the focus position of the spherical lens 60 of the GaP light emitting diode LED2, the infrared light is a parallel light beam above the GaP light emitting diode LED2. And radiate. On the other hand, when a forward current is passed through the GaP light emitting diode LED2, yellow-green light having a peak wavelength of about 0.56 μm is emitted from the pn junction 63. That is, when a forward current is applied to each of the light emitting diodes LED2 and LED4, two types of light with different wavelengths are emitted along the same optical axis. It is possible to independently emit light of two types of wavelengths on the same optical axis, and to perform optical communication of two types of wavelengths, optical measurement,
It can be used for optical spectroscopy. Also, the light emitted from the GaP light emitting diode LED2 can be used as a guide for invisible infrared light. In addition, like the first embodiment, the size can be reduced, the configuration can be simplified, and the semiconductor material can be reduced.
The manufacturing cost can be reduced, and a semiconductor device useful in the fields of optical communication, optical information processing, spectroscopic analysis, optical sensor, etc. can be realized.

An infrared light emitting diode of 1 μm band using InGaAsP / InP is used in place of the infrared light emitting diode LED4 of GaAlAs shown in FIGS. 12 and 13, and a spherical GaAlAs infrared light is used in place of the GaP light emitting diode LED2. With light emitting diode
It is also possible to make a composite light emitting diode that combines infrared light emitting diodes in the 1 μm band using InGaAsP / InP to make a composite light emitting diode of two types of wavelengths.

Embodiment 7: "Light-Emitting and Emitting Compound Diode" A light-receiving and emitting compound diode in which an InGaAsP / InP photodiode PD4 of the fifth embodiment is replaced by an InGaAsP / InP infrared light emitting diode having a peak wavelength of 1.55 μm is used. create. With this combined light emitting and receiving diode, about 1.1 μm
The following external optical signal can be detected by the silicon photodiode PD1, and conversely, an infrared optical signal with a peak wavelength of 1.55 μm can be emitted to the outside. Therefore, this composite light emitting and receiving diode can be used for bidirectional optical communication using two types of light having different wavelengths. The lens may be spherical, hemispherical, rod-shaped, cylinder-shaped, round-drum-shaped, convex-shaped or the like as long as it can convert the traveling direction of light into a desired direction by refraction.

Embodiment 8: "Receiving and Emitting Compound Diode" Instead of the GaAlAs infrared light emitting diode LED4 of Embodiment 6.
It is also possible to make a light emitting / receiving composite diode that incorporates an InGaAs / InP photodiode. When a material such as a GaP light emitting diode that absorbs light with a relatively short wavelength is converted into infrared light with a relatively long wavelength and reflected, it is used as a mark, and this is illuminated by a light emitting and receiving complex diode. If so, the reflected light can be detected by the InGaAs / InP photodiode and can be used as a mark sensor.

Needless to say, referring to the embodiments of the present invention described above, it is possible to fabricate a light emitting and receiving composite diode having the same function as the present invention by combining various light receiving and emitting light devices based on the existing technology. In addition, in the above-described embodiment, the present invention includes a bulk structure photoconductive element having photoconductive characteristics such as a phototransistor and PbS, PbSe, and CdS as the light receiving device regardless of the presence or absence of the lens function, in addition to the photodiode. Can be implemented.

[0054]

According to the invention of claim 1, as described above, since a lens function is obtained by effectively utilizing a part of the optical path formed by the light-transmittable semiconductor , the size can be reduced. The structure can be simplified, the semiconductor material can be saved, and the manufacturing cost can be reduced. Moreover, by combining with an external light receiving device, two types of incident light can be independently photoelectrically converted, and light having an increased energy density can be photoelectrically converted by the light receiving device with high sensitivity. In addition, by combining with an external light emitting device, incident light can be received and photoelectrically converted, and emitted light can be emitted.

According to the invention of claim 2, as described above,
A lens function is obtained by effectively utilizing a part of an optical path formed by a light-transmittable semiconductor, so that the size can be reduced, the configuration can be simplified, the semiconductor material can be saved, and the manufacturing cost can be reduced. . Moreover, by combining with an external light emitting device, two types of light can be independently generated and emitted. Also, by combining with an external light receiving device, it becomes possible to perform high-sensitivity photoelectric conversion by allowing the light receiving device to receive the light whose energy density is increased by the lens function.

According to the invention of claim 3, as described above,
Since the light receiving section and the second light receiving section can independently receive two types of incident light having different wavelengths and perform photoelectric conversion, a semiconductor device useful in the fields of optical communication, optical information processing, spectroscopic analysis, optical sensor, and the like. Can be provided. Others, claim 1
Similarly, the size can be reduced, the configuration can be simplified, the semiconductor material can be saved, and the manufacturing cost can be reduced.

According to the invention of claim 4, as described above,
For example, in the case of being configured to receive light of a short wavelength and emit light of a long wavelength of two types of light having different wavelengths, it is possible to provide a light emitting device applicable to bidirectional optical communication, and It is also possible to provide a semiconductor device for an optical sensor having both functions of light emission. Others, claim 1
Similarly, the size can be reduced, the configuration can be simplified, the semiconductor material can be saved, and the manufacturing cost can be reduced. Similarly to the third aspect, it is possible to provide a semiconductor device useful in the fields of optical communication, optical information processing, spectroscopic analysis, optical sensor and the like.

According to the invention of claim 5, as described above,
Since the light emitting unit and the second light emitting unit can independently emit two types of light having different wavelengths, it is possible to provide a semiconductor device useful in the fields of optical communication, optical information processing, spectroscopic analysis, optical sensors, and the like. it can. Besides, as in the first aspect, the size can be reduced, the configuration can be simplified, the semiconductor material can be saved, and the manufacturing cost can be reduced.

According to the invention of claim 6, as described above,
Similarly to the third aspect, it is possible to provide a light emitting device to which bidirectional optical communication can be applied. It is also possible to provide a semiconductor device for an optical sensor having both a light receiving function and a light emitting function. Others, like the first aspect, can be downsized,
The structure can be simplified, the semiconductor material can be saved, and the manufacturing cost can be reduced.

[Brief description of drawings]

FIG. 1 is a sectional view of a silicon photodiode according to a first embodiment of the present invention.

FIG. 2 is a bottom view of the silicon photodiode of FIG.

FIG. 3 is a sectional view of a silicon photodiode according to a second embodiment.

FIG. 4 is a bottom view of the silicon photodiode of FIG.

FIG. 5 is a sectional view of a light emitting diode according to a third embodiment.

FIG. 6 is a plan view of the light emitting diode of FIG.

FIG. 7 is a sectional view of a light emitting diode according to a fourth embodiment.

FIG. 8 is a plan view of the light emitting diode of FIG.

9 is a side view of the light emitting diode of FIG. 7. FIG.

FIG. 10 is a sectional view of a composite photodiode according to a fifth embodiment.

11 is a plan view of the composite photodiode of FIG.

FIG. 12 is a sectional view of a composite photodiode according to a sixth embodiment.

13 is a plan view of the composite photodiode of FIG.

[Explanation of symbols]

PD1 Silicon photodiode with hemispherical lens 1 Silicon substrate 2 Hemispherical lens 4 n ⁺ p junction (light receiving part) 8 Optical path PD2 Silicon photodiode with hemispherical lens 21 Silicon substrate 22 Hemispherical lens 25 n ⁺ p junction (light receiving part) 26 Optical path LED1 Light emitting diode with hemispherical lens 41 Crystal substrate 42 Hemispherical lens 47 pn junction (light emitting part) 51 Optical path LED2 Spherical light emitting diode 61 p-type GaP crystal 63 pn junction (light emitting part) 66 Optical path PD3 Composite photodiode PD4 InGaAs / InP photodiode 71 crystal substrate 77 pn junction (light receiving portion) LED3 composite type light emitting diode LED4 infrared light emitting diode 81 crystal substrate 86 pn junction (light emitting portion)

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-7-110454 (JP, A) JP-A-4-30126 (JP, A) JP-A-4-30127 (JP, A) JP-A-4-30127 30128 (JP, A) JP-A-7-92509 (JP, A) JP-A-4-363072 (JP, A) JP-A-55-30828 (JP, A) JP-A-53-135588 (JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) H01L 31/00-31/12 H01L 33/00

Claims (6)

(57) [Claims] 1. A Oite a semiconductor device having a light receiving section that photoelectrically converts incident light, the light receiving portion of the light transmissive semiconductor
It constitutes a part, transmitted through the light receiving portion in the light transmissive semiconductor
A semiconductor device with an optical lens function, characterized in that an optical path for transmitting the above-mentioned light or light directed to a light receiving portion is formed, and a lens function is added to a part of this optical path. 2. A semiconductor device having a light emitting portion for converting electric energy into light, which comprises a part of a light transmitting semiconductor and the light transmitting semiconductor.
A semiconductor device with an optical lens function, characterized in that an optical path for transmitting light emitted from a light emitting portion is formed, and a lens function is added to a part of this optical path. 3. The second light receiving section for photoelectrically converting incident light is integrally incorporated, and the second light receiving section receives the incident light transmitted through the optical path. Semiconductor device with optical lens function. 4. A light emitting section for converting electric energy into light, which is integrated with the light emitting section, is constructed such that light emitted from the light emitting section is transmitted through the optical path and emitted. A semiconductor device with an optical lens function as described above. 5. A second method for converting electric energy into light
The semiconductor device with an optical lens function according to claim 2, wherein the light emitting portion is integrally incorporated, and the light emitted from the second light emitting portion is configured to be emitted through the optical path. 6. The optical lens function according to claim 2, wherein a light receiving section for photoelectrically converting the incident light is integrally incorporated, and the incident light transmitted through the optical path is received by the light receiving section. Semiconductor device.