JPH0936414A - Light emitting/receiving element and fabrication thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a light emitting/receiving element, and a fabrication method thereof, in which high light emitting quantity and light receiving quantity can be attained with high efficiency. SOLUTION: A Zn doped P type diffusion region 2 is formed on an N type GaAsP or N type GaAlAs epitaxial substrate 1 thus forming a PN junction closely to the end face of substrate and the driving voltage is switched to emit light or receive light.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light emitting / receiving element and a method for manufacturing the same.

[0002]

2. Description of the Related Art Hitherto, various types of exposure light sources and image sensors have been proposed for an electrophotographic copying machine, a printer, a scanner, a facsimile or a composite machine of these. For example, JP-A-56-122
In the devices disclosed in JP-A-069 and JP-A-58-157252, an LED (Light Emit) is disclosed.
toning diode array is used for both the exposure light source and the image sensor.

This is because if a forward voltage is applied to the PN junction of an LED to inject carriers, light is emitted by recombination of the carriers, and a reverse voltage is applied to the PN junction of the LED to irradiate light. For example, the LED array is used as both an exposure light source and an image sensor, paying attention to the fact that a photocurrent can be obtained by generating carriers. In the exposure light source and the image sensor, the top emission type L
The ED was being used.

[0004]

Conventional Top-Emitting LE
In manufacturing D, a diffusion mask is generally formed on a substrate, and impurities are selectively diffused through a diffusion window of the diffusion mask to form a PN junction. At this time, a deep PN junction having a uniform depth is formed over the entire surface inside the diffusion window, but a shallow PN junction is formed in a narrow linear region on the window peripheral portion outside the diffusion window due to side diffusion of impurities. .

In the top emitting LED, the diffusion depth (X
_As shown in FIG. 27, the relationship between _j ) and the emission intensity is
The emission intensity increases up to a certain diffusion depth a of X _j max,
The emission intensity decreases at the peak of X _j max. However, although there is some difference in X _j max due to the difference in the manufacturing method, this tendency generally holds.

On the other hand, the relationship between the diffusion depth X _j and the photosensitivity is
As shown in FIG. 28, the light receiving sensitivity increases as X _j decreases. Here, the measurement of the light receiving sensitivity was performed with the irradiation light of 550 nm suitable for reading the manuscript of red characters. As described above, since in the case of performing efficiently receiving and emitting light in top-emitting LED is, X _j max as luminous intensity becomes the maximum, also the light receiving sensitivity must be X _j that maximizes, It was impossible to efficiently receive and emit light with one device.

Further, since the size of one chip of the top emission type LED becomes large, there is a problem that the cost becomes high. Therefore, an attempt was made to use an edge emitting LED as a light emitting / receiving element, which has high light emitting and light receiving efficiency and is small in size and capable of a low cost process. However, since the emission diameter is small with respect to light emission, it is necessary to lengthen the exposure time in order to obtain the same emission diameter as that of the top-emission LED, and the light receiving area is small with respect to light reception, which is sufficient for the irradiation light. There was a problem that no signal was obtained.

Therefore, the present invention eliminates the above problems,
It is an object of the present invention to provide a light emitting and receiving element which has high light receiving and emitting efficiency and which can obtain a sufficient amount of emitted light and an amount of received light, and a method for manufacturing the same.

[0009]

In order to achieve the above object, the present invention provides (1) a receiving layer comprising a diffusion layer formed by diffusing impurities of a second conductivity type into a compound semiconductor substrate of a first conductivity type. In the light emitting element, a PN junction formed in the vicinity of the end face of the substrate is adapted to emit light or receive light from the end face side of the substrate by switching the drive voltage.

(2) In the light emitting and receiving element according to the above (1), a part of the first conductivity type region is left in the vicinity of the end face of the substrate. (3) In the light emitting / receiving element according to the above (1), the PN
The junctions are provided so as to extend near both end faces of the opposing substrates, and light is received by a PN junction located near one of the substrate end faces and emitted by a PN junction located near the other substrate end face. It is a thing.

(4) In the light emitting / receiving element described in (3) above, the diffusion depth of the light receiving portion is deeper than the diffusion depth of the light emitting portion. (5) In the light emitting / receiving element according to (1), (2), (3) or (4) above, from the substrate end face side of a PN junction formed near the substrate end face based on the diffusion depth from the substrate main surface. The amount of light emission or the amount of light reception is controlled by controlling the viewed area.

(6) A step of laminating a diffusion barrier film on the first conductivity type compound semiconductor substrate in the method for manufacturing a light receiving and emitting device in which the impurities of the second conductivity type are diffused in the first conductivity type compound semiconductor substrate. And forming a diffusion window in the diffusion prevention film,
A step of covering the exposed region of the first conductivity type with a diffusion control film, diffusing impurities through the diffusion control film to form a diffusion region of the second conductivity type, and the first conductivity type near the end face of the substrate. And a step of partially etching the compound semiconductor substrate of the first conductivity type adjacent to the diffusion region of the second conductivity type so that a part of the region remains.

(7) In a method of manufacturing a light emitting / receiving device in which a second conductivity type impurity is diffused in a first conductivity type compound semiconductor substrate, a step of laminating a diffusion barrier film on the first conductivity type compound semiconductor substrate. And forming a diffusion window in the diffusion prevention film,
Both the step of exposing the region of the first conductivity type and the region of making the diffusion depth in the exposed region of the first conductivity type shallow and the region of making the diffusion depth deep are covered with a diffusion control film, and the film of the diffusion control film is formed. A second conductivity type in which the diffusion depth is shallow and the impurity is diffused through the diffusion control film to make the diffusion layer thicker on the region where the diffusion depth is formed shallower and thin on the region where the diffusion depth is formed deeper. Forming a first diffusion region and a second diffusion region of the second conductivity type having a deep diffusion depth, and diffusing the second conductivity type so that a part of the second conductivity type region remains in the vicinity of the end face of the substrate. And a step of partially etching the first conductivity type compound semiconductor substrate adjacent to the region.

[0014]

[Action]

(1) According to the light emitting and receiving element of the first aspect, by switching the drive voltage at the PN junction formed near the end face of the substrate,
Since the structure is such that it receives or emits light, a single element can receive and emit light without being affected by the light absorption layer. (2) According to the light emitting / receiving element of the second aspect, in the vicinity of the end face of the substrate, only a part of the substrate, which is a region where the diffusion layer and the depletion layer region of the hole are formed, is left. The PN junction formed in the end face direction of the substrate can receive and emit light with almost no influence of the absorption layer.

(3) According to the light emitting and receiving element of the third aspect, the PN junction is provided so as to extend near both end faces of the opposing substrates, and the PN junction located near one end face of the substrate receives light. Since the light is emitted from the other PN junction, the single element can receive and emit light, and the conditions of the light emitting portion and the light receiving portion can be changed.

(4) According to the light receiving and emitting device of the fourth aspect, since the diffusion depth of the light receiving portion is deeper than the diffusion depth of the light emitting portion, the light emitting portion is used as a light receiving portion. It is possible to increase the PN junction area and increase the amount of received light. (5) According to the light emitting / receiving element of the fifth aspect, the area of the PN junction formed in the vicinity of the substrate end face viewed from the substrate end face side is controlled based on the diffusion depth from the substrate main surface, and the light emission amount and the light receiving amount are received. Since the amount is controlled, it is possible to obtain the optimal light emission amount and light reception amount.

(6) According to the method for manufacturing a light emitting and receiving element of the sixth aspect, since the PN junction near the end face of the substrate formed by etching is used as the light receiving and emitting portion, it is not affected by the light absorbing layer. It is possible to receive and emit light, have a small size, and reduce the manufacturing cost. (7) According to the method for manufacturing a light emitting and receiving element of claim 7,
In addition to the effect of (6) above, the PN junction area on the light receiving portion side can be formed to be larger than that on the light emitting portion side, and the light receiving amount can be increased.

[0018]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a configuration diagram of a light emitting / receiving element showing a first embodiment of the present invention, FIG. 1 (a) is a perspective view of the light emitting / receiving element, and FIG. 1 (b) is a top view of the light receiving / emitting element.
1C is a sectional view taken along the line AA of FIG. 1A, and FIG.
FIG. 4 is a front view of the light emitting / receiving element.

Here, 1 is N-type GaAsP or N-type Ga
AlAs epitaxial substrate (hereinafter, simply referred to as substrate), 2 is a Zn-doped P-type diffusion region, 3 is Al ₂ O ₃
Is a P-side electrode made of Al, and 5 is an N-side electrode made of Au alloy. As shown in FIG.
In the light emitting / receiving device of this embodiment, a diffusion barrier film 3 is provided on an N type epitaxial layer, and Zn doped P type impurities are diffused through the diffusion window to form a P type diffusion region 2. Is used to form a PN junction, and the end face of the substrate 1 is further etched to form a PN junction between the P type diffusion region 2 and the N type region existing in the vicinity of the end face of the substrate.

When light is emitted and received by this light emitting and receiving element, the structure is such that only a part of the substrate (designed value: the diffusion length of holes and the region where the depletion layer region is formed) remains on the end face of the substrate. The PN junction formed in the end face direction of the substrate can receive and emit light with almost no influence of the light absorption layer. That is, the end surface of the substrate is formed of a surface that intersects with the main surface of the semiconductor underlayer at a position separated from the end of the P-type diffusion region 2 by the predetermined distance α. This predetermined (appropriate) distance is
Although it differs in light receiving and light emitting functions, in any case, it can be mainly defined by the sum of the depletion layer formed in the vicinity of the light receiving and emitting portion (PN junction portion) and the hole diffusion length. The width of the depletion layer varies depending on the driving voltage, and the hole diffusion length varies depending on the wavelength of light to be received. In any case, the appropriate distance is several μm to several tens.
μm.

Further, the area of the PN junction formed in the substrate end face direction can be controlled by changing the P-type diffusion or the diffusion depth. As described above, the PN junction formed in the end face direction of the substrate receives and emits light. As shown in FIG. 2, when light is emitted and received by the light emitting and receiving element of the first embodiment of the present invention, when a forward bias voltage is applied to the end face light emitting and receiving type LED array and carriers are injected, near the PN junction is generated. Light is emitted by recombination of electrons and holes. On the other hand, when a reverse bias voltage is applied and irradiated with irradiation light, photocarriers are generated near the PN junction, and holes are generated on the P side of the depletion layer region.
Electrons are accumulated on the N side.

In the LED array having the above structure, the light emitting / receiving function can be obtained with one dot by switching the bias in the forward and reverse directions. Next, a method of manufacturing the light emitting / receiving element of the first embodiment of the present invention will be described. 3 to 9 are manufacturing process diagrams of the light receiving and emitting device according to the first embodiment of the present invention. In each figure, (a) is a plan view, (b) is a vertical direction (AB line) sectional view of the plan view, and (c) is a lateral direction (CD line) sectional view of the plan view. Is.

(1) First, as shown in FIGS. 3A to 3C, a diffusion prevention film 102 is laminated on the N-type semiconductor region 101. In this embodiment, an N-type GaAs _0.8 P _0.2 substrate is used as the N-type semiconductor region 101, and an Al ₂ O ₃ film is used as the diffusion prevention film 102. (2) Next, as shown in FIGS. 4A to 4C, a diffusion window 103 is provided in the diffusion prevention film 102 stacked on the N-type semiconductor region 101. In this embodiment, the diffusion window 103 is formed using photolithography and etching techniques.

(3) Next, as shown in FIGS. 5A to 5C, a diffusion control film 104 is laminated on the N-type semiconductor region 101 of the diffusion window 103 of the diffusion prevention film 102, and its diffusion control is performed. Impurities are introduced through the film 104, and the P-type semiconductor region 10
5 is formed. Here, PS is used as the diffusion control film 104.
A G film, a SiO ₂ film, an Al ₂ O ₃ film or a SiN film is laminated.

(4) Next, as shown in FIGS. 6A to 6C, the diffusion control film 104 [see FIG. 5] is entirely peeled off,
The metal film 106 to be the P-side electrode and the N-side electrode 107 are laminated. In this embodiment, an Al film is used as the metal film 106 serving as the P-side electrode, and an Au alloy is used as the N-side electrode 107.

(5) Then, as shown in FIGS. 7A to 7C, a resist 108 is applied to form a P-side electrode and photolithography is performed. (6) Next, as shown in FIGS. 8A to 8C, the metal film 106 serving as the P-side electrode is etched to remove the P-side electrode 106.
a is formed, and is covered with a resist 108 that is an etching prevention film so that the P-type semiconductor region 105 and a part of the N-type semiconductor region 101 remain.

(7) Next, as shown in FIGS. 9A to 9C, the N-type semiconductor region 101 is etched so that the P-type semiconductor region 105 and a part of the N-type semiconductor region 101 remain. . Finally, the portion indicated by the dotted line is diced to complete the light emitting / receiving element. FIG. 10 is a configuration diagram of a light emitting / receiving element showing a second embodiment of the present invention.
10A is a perspective view of the light emitting / receiving element, FIG. 10B is a top view of the light emitting / receiving element, and FIG. 10C is A of FIG. 10A.
FIG. 10D is a front view of the light emitting / receiving element, taken along the line A-A.

Here, 11 is a substrate (N-type GaAsP or N-type GaAlAs epitaxial substrate), 12 is a Zn-doped P-type diffusion region, 13 is a diffusion prevention film made of Al ₂ O ₃ , and 14 is a P side made of Al. The electrode 15 is an N-side electrode made of Au alloy. In this light emitting / receiving element, a diffusion prevention film is provided on an N type epitaxial layer, and P type impurities are diffused through the diffusion window to form a P type diffusion region 12, thereby forming a PN junction. This is a structure in which the substrate 11 is partially etched, and a part of the N-type semiconductor region adjacent to the P-type diffusion region in the vicinity of the end face of the substrate remains.

As shown in FIG. 11, when light is received and emitted by the light emitting and receiving device of the second embodiment of the present invention, a part of the substrate (designed value: diffusion length of hole and depletion layer region is formed at the end face of the substrate. Since it has a structure in which only the (region to be formed) remains, it is possible to receive and emit light by the PN junction formed in the end face direction of the substrate with almost no influence of the light absorption layer. That is, the end surface of the substrate is a surface that intersects with the main surface of the semiconductor base at a position separated from the end of the P-type diffusion region 12 by a predetermined distance α. This predetermined (appropriate) distance differs depending on the light receiving and light emitting functions, but in any case, the light receiving and emitting section (PN junction section)
It can be mainly defined by the sum of the depletion layer formed in the vicinity and the hole diffusion length. This depletion layer width changes depending on the driving voltage, and the hole diffusion length changes depending on the wavelength of the light to be received, but in any case, the appropriate distance is several μm to several tens of μm.

In this embodiment, as shown in FIG. 11, one end face of the substrate formed by etching is made to emit light, and the other end face is made to receive light, that is, both end faces are made to receive and emit light. That is, when a forward bias voltage is applied to the end face light emitting and receiving type LED array shown in FIG. 11 and carriers are injected, light is emitted by recombination of electrons and holes near the PN junction. On the other hand, when a reverse bias voltage is applied and irradiation light is irradiated, photocarriers are generated near the PN junction, and holes are accumulated on the P side and electrons are accumulated on the N side of the depletion layer region.

By changing the diffusion depth,
The PN junction area formed in the substrate end face direction can be controlled.
Further, in the above structure, the PN formed on the end face of the substrate
Since light is emitted and received by joining, it is possible to obtain an effect that the element size is small and the manufacturing cost can be reduced. In the LED array having the above structure, the light emitting / receiving function can be obtained with one dot by switching the bias in the forward direction and the bias in the reverse direction.

Next, a method of manufacturing the light emitting / receiving element shown in the second embodiment of the present invention will be described. 12 to 15 are main manufacturing process diagrams of the light emitting and receiving element shown in the second embodiment of the present invention. The diffusion preventing film laminating step, the diffusion preventing film photolitho-etching step, the diffusion controlling film laminating step and the diffusion step in this embodiment will be described with reference to FIG.
-The steps are the same as (1), (2) and (3) shown in FIG.

Hereinafter, description will be made in the order of (4) to (7). (4) As shown in FIG. 12, the diffusion control film (not shown) is entirely peeled off, a metal film (Al film) serving as a P-side electrode is laminated, and then the P-side electrode 11 is formed by photolithography etching.
3 is formed. In this figure, 111 is a substrate (N type G
aAsP or N-type GaAlAs epitaxial substrate),
Reference numeral 112 is a diffusion prevention film, and 114 is a P-type semiconductor region.

(5) Next, as shown in FIG. 13, an opening is provided in the portion where the N-side electrode is to be formed, and a metal film (Au alloy film) which will serve as the N-side electrode is laminated and further photolithographic etching is performed. Thus, the N-side electrode 116 is formed. (6) Next, as shown in FIG. 14, the P-type semiconductor region 11 is formed.
4 and a part of the N-type semiconductor region are covered with a resist 117 which is an etching prevention film so as to remain.

(7) Next, as shown in FIG. 15, the N-type semiconductor region is etched so that the P-type semiconductor region 114 and a part of the N-type semiconductor region remain. Finally, the light emitting and receiving element is completed by dicing the portion indicated by the dotted line. 16 is a configuration diagram of a light emitting / receiving element showing a third embodiment of the present invention, FIG. 16 (a) is a perspective view of the light emitting / receiving element, and FIG. 16 (b) is a top view of the light receiving / emitting element. 16
16C is a sectional view taken along the line AA of FIG. 16A, FIG.
FIG. 4 is a front view of the light emitting / receiving element.

This embodiment is an improvement made by widening the light receiving area of the light receiving portion shown in the second embodiment. Here, 21 is a substrate (N-type GaAsP or N-type Ga)
AlAs epitaxial substrate), 22 is Zn-doped P
Diffusion region, 23 is a diffusion mask made of Al ₂ O ₃ , 2
4 is a P-side electrode made of Al, and 25 is N made of an Au alloy.
It is a side electrode.

As shown in FIG. 17, when the light emitting / receiving element of the third embodiment of the present invention receives and emits light, one end face of the substrate formed by etching is made to emit light and the other end face is made to receive light. That is, the structure is such that both end faces receive and emit light, and further, in this light receiving and emitting element, the diffusion depth of the P type diffusion region 22b on the light receiving portion side is formed deeper than the P type diffusion region 22a on the light emitting portion side. By doing so, the PN junction area viewed from the substrate end surface side which becomes the light receiving portion is increased, and the amount of light received is increased.

That is, the edge receiving / emitting type L shown in FIG.
When a forward bias voltage is applied to the ED array and carriers are injected, light is emitted by recombination of electrons and holes near the PN junction. On the other hand, when a reverse bias voltage is applied and irradiation light is irradiated, photocarriers are generated near the PN junction, and holes are accumulated on the P side and electrons are accumulated on the N side of the depletion layer region.

In the LED array having the above structure, the light emitting / receiving function can be obtained with one dot by switching the bias in the forward direction and the bias in the reverse direction. Next, a method of manufacturing the light emitting / receiving element shown in the third embodiment of the present invention will be described. 18 to 24
FIG. 7 is a main manufacturing process diagram of the light emitting / receiving element shown in the third embodiment of the present invention.

The diffusion preventing film laminating step and the diffusion preventing film photolithographic etching step in this embodiment are shown in FIGS. 3 to 4 of the first embodiment (1) and (2).
Since it is the same process as above, it is omitted. (3) First, as shown in FIG. 18, a PSG film and SiO are formed on the N-type semiconductor region 121 of the diffusion window of the diffusion prevention film 122.
_A first diffusion control film 123 composed of _two films, an Al ₂ O ₃ film, a SiN film or the like is laminated.

(4) Next, as shown in FIG. 19, the first diffusion control film 123 is left by a photolithography etching method so that only a portion where a shallow diffusion depth is formed remains, and a second diffusion control film 124 is further laminated. To do. Impurities are introduced through the first and second diffusion control films 123 and 124 to form P-type semiconductor regions 125 having different diffusion depths. Then the second
The diffusion control film 124 is peeled off.

(5) Next, as shown in FIG. 20, a metal film 126 made of an Al film to be a P-side electrode is laminated. (6) Next, as shown in FIG. 21, a P-side electrode 126a is formed on the metal film 126 by photolithography etching. (7) Next, as shown in FIG. 22, an opening is provided in a portion where an N-side electrode is to be formed, N-side electrode films are laminated, and further, N-side electrode 1 made of an Au alloy is formed by photolithography etching.
27 are formed.

(8) Next, as shown in FIG. 23, the resist 12 as an etching prevention film is formed so that the P-type semiconductor region 125 and a part of the N-type semiconductor region 121 remain.
Cover with 8. (9) Next, as shown in FIG. 24, the P-type semiconductor region 12
The N-type semiconductor region 121 is etched so that 5 and a part of the N-type semiconductor region 121 remain. Finally, the light emitting and receiving element is completed by dicing the portion indicated by the dotted line.

In the second and third embodiments described above, P
By providing the side electrode and the N-side electrode on the upper surface of the array,
The LED array can be mounted on the driver IC. 25 is a block diagram of a module including a light emitting / receiving element and a driver IC according to the fourth embodiment of the present invention.
FIG. 25A is a perspective view of the LED array, and FIG.
25 (c) is a side view of the LED array, and FIG. 25 (d) is a front view of the LED array.

In FIG. 25, 131 is a driver IC,
Reference numerals 132 and 133 denote converging rod lens arrays for the light receiving portion and the light emitting portion, respectively, and 134 denotes a light receiving and emitting element.
The light emitting / receiving element 134 on the driver IC 131 is electrically connected by bump connection. Here, bump connection means connection by solder, connection by thermosetting resin, connection by anisotropic conductive resin, or the like. This mounting method can reduce the size of the head.

By mounting the driver IC and the light emitting / receiving element module as described above on the substrate,
A read / write head and a read / write device as shown in FIG. 6 can be configured. Here, 141 is a light emitting / receiving element, and 14
Reference numeral 2 is a driver IC, 144 and 145 are converging rod lens arrays for writing and reading, 146 is an illumination light source, 147 is a document, 148 is a document setting glass, and 14
9 is a developing machine, 150 is a charger, 151 is a photosensitive drum, 1
Reference numeral 52 is a transfer machine, and 153 is paper.

In this apparatus, the reading original 147 is scanned on the glass substrate, and the original 147 is illuminated by the illumination light source 146, and the reflected light passes through the reading converging / converging rod lens array 145 and is received. Light emitting element 14
The light is incident on the first light receiving portion (reading portion) and converted into an electric signal.
The printing is performed in the same manner as described above. By using this light emitting / receiving element, reading / writing can also be performed without mechanically driving the head.

The present invention is not limited to the above embodiments, and various modifications can be made based on the spirit of the present invention, and these modifications are not excluded from the scope of the present invention.

[0049]

As described in detail above, according to the present invention, the following effects can be achieved. (1) According to the first aspect of the invention, the PN junction formed in the vicinity of the end face of the substrate is configured to receive or emit light by switching the drive voltage. The device can receive and emit light.

(2) According to the second aspect of the present invention, only a part of the substrate, which is the region where the diffusion layer and the depletion layer region of the hole are formed, is left at the end face of the substrate. Light can be emitted and received by the PN junction formed in the direction of the end face of the substrate without being affected by the layers. (3) According to the invention of claim 3, the PN junction is provided so as to extend in the vicinity of both end faces of the opposing substrates, and light is received by the PN junction located in the vicinity of one of the substrate end faces. Since light is received by the PN junction located near the end face of one of the substrates, light can be received and emitted by a single element, and the conditions of the light emitting portion and the light receiving portion can be changed.

(4) According to the invention described in claim 4, when one of the PN junctions functions as the light receiving portion, the diffusion depth of the light receiving portion is set to be deeper than the diffusion depth of the light emitting portion. It is possible to increase the amount of light received by increasing the PN junction area that serves as a light receiving portion with respect to the light emitting portion. (5) According to the invention described in claim 5, the PN junction area of the substrate end face is controlled based on the diffusion depth from the main surface of the substrate, and the optimal light emission amount is obtained by controlling the light emission amount and the light reception amount. The amount of received light can be obtained.

(6) According to the sixth aspect of the invention, the PN junction can be provided in the vicinity of the end face of the substrate formed by etching, light can be emitted and received without being affected by the light absorption layer, and the size is small. Moreover, the manufacturing cost can be reduced. (7) According to the invention of claim 7, in addition to the effect of the above (6), it can be formed so that the PN junction area on the light receiving portion side is larger than that on the light emitting portion side. Can be increased.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a light emitting / receiving element showing a first embodiment of the present invention.

FIG. 2 is an explanatory diagram of an operation of the light emitting / receiving element showing the first embodiment of the present invention.

FIG. 3 is a first manufacturing process diagram of the light emitting and receiving device of the first embodiment of the present invention.

FIG. 4 is a second manufacturing process drawing of the light emitting and receiving element of the first embodiment of the present invention.

FIG. 5 is a third manufacturing process diagram of the light emitting / receiving element of the first embodiment of the present invention.

FIG. 6 is a fourth manufacturing process diagram of the light emitting / receiving element of the first embodiment of the present invention.

FIG. 7 is a fifth manufacturing process drawing of the light emitting and receiving device of the first embodiment of the present invention.

FIG. 8 is a sixth manufacturing process drawing of the light emitting / receiving element of the first embodiment of the present invention.

FIG. 9 is a seventh manufacturing process drawing of the light emitting and receiving device of the first embodiment of the present invention.

FIG. 10 is a configuration diagram of a light emitting / receiving element showing a second embodiment of the present invention.

FIG. 11 is an explanatory diagram of the operation of the light emitting / receiving element showing the second embodiment of the present invention.

FIG. 12 is a fourth manufacturing process diagram of the light emitting / receiving element of the second embodiment of the present invention.

FIG. 13 is a fifth manufacturing process drawing of the light emitting and receiving device of the second embodiment of the present invention.

FIG. 14 is a sixth manufacturing process drawing of the light emitting and receiving device of the second embodiment of the present invention.

FIG. 15 is a seventh manufacturing step diagram of the light emitting / receiving element of the second embodiment of the present invention.

FIG. 16 is a configuration diagram of a light emitting / receiving element showing a third embodiment of the present invention.

FIG. 17 is an explanatory diagram of the operation of the light emitting / receiving element showing the third embodiment of the present invention.

FIG. 18 is a third manufacturing step diagram of the light emitting / receiving element of the third embodiment of the present invention.

FIG. 19 is a fourth manufacturing process diagram of the light emitting / receiving element of the third embodiment of the present invention.

FIG. 20 is a fifth manufacturing process diagram of the light emitting and receiving device of the third embodiment of the invention.

FIG. 21 is a sixth manufacturing process drawing of the light emitting / receiving element of the third embodiment of the present invention.

FIG. 22 is a seventh manufacturing step diagram of the light emitting / receiving element of the third embodiment of the present invention.

FIG. 23 is an eighth manufacturing process diagram of the light emitting and receiving device of the third embodiment of the invention.

FIG. 24 is a ninth manufacturing process diagram of the light emitting and receiving device of the third embodiment of the invention.

FIG. 25 is a configuration diagram of a module including a light emitting / receiving element and a driver IC according to a fourth embodiment of the present invention.

FIG. 26 is a diagram showing a read / write head and a read / write device to which a module of a light emitting / receiving element and a driver IC according to a fourth embodiment of the present invention is applied.

FIG. 27: Diffusion depth (X _j ) of a conventional top-emitting LED
It is a figure which shows the relationship between and the light emission intensity.

FIG. 28 is a diagram showing the relationship between the diffusion depth and the light receiving sensitivity of a conventional top-emitting LED.

[Explanation of symbols]

1,11,21,111 N-type GaAsP or N-type G
aAlAs epitaxial substrate 2,12,22 Zn-doped P-type diffusion region 3,13,23 Diffusion prevention film made of Al ₂ O ₃ 4,14,24,106a, 113,126a Al
P-side electrode 5,15,25,107,116,127 N-side electrode 22a made of Au alloy 22a P-type diffusion region 22b on the light-emitting side 22b P-type diffusion region 101,121 on the light-receiving side 101-121 N-type semiconductor region (N Type GaAs _0.8
P _0.2 substrate) 102, 112, 122 Diffusion prevention film (Al ₂ O
₃ film) 103 diffusion window 104 diffusion control film (PSG film, SiO ₂ film, Al ₂
O ₃ film or SiN film) 105, 114, 125 P-type semiconductor region 106, 126 Metal film 108, 117, 128 Resist 123 First diffusion control film 124 Second diffusion control film 131, 142 Driver IC 132, 133 For light receiving part Focusing rod lens array 134, 141 for light emitting part and light receiving / emitting element 144, 145 Focusing rod lens array for writing and reading 146 Illumination light source 147 Original 148 Original setting glass 149 Developing machine 150 Charger 151 Photosensitive drum 152 Transfer machine 153 paper

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical display location B41J 2/45 H01L 31/10 A 2/455 H01L 31/10 (72) Inventor Hiroyuki Fujiwara Tokyo 1-7-12 Toranomon, Minato-ku Oki Electric Industry Co., Ltd.

Claims (7)

[Claims] 1. A light emitting and receiving element comprising a diffusion layer formed by diffusing impurities of a second conductivity type in a compound semiconductor substrate of a first conductivity type, wherein a driving voltage is switched by a PN junction formed near an end face of the substrate. A light emitting / receiving element characterized in that light is emitted or received from an end face side of a substrate. 2. The light emitting / receiving element according to claim 1, wherein a part of the first conductivity type region is left in the vicinity of the end face of the substrate. 3. The light emitting and receiving element according to claim 1, wherein the PN junction is provided so as to extend near both end faces of the opposing substrates, and light is received by the PN junction located near one end face of the substrate. A light emitting and receiving device, characterized in that light is emitted from a PN junction located near the end face of the other substrate. 4. The light emitting / receiving element according to claim 3, wherein the diffusion depth of the light receiving portion is deeper than the diffusion depth of the light emitting portion. 5. The light receiving and emitting device according to claim 1, 2, 3 or 4, wherein the area of the PN junction formed near the substrate end face viewed from the substrate end face side is controlled based on the diffusion depth from the substrate main surface. The light emitting / receiving element is characterized in that the light emitting amount or the light receiving amount is controlled. 6. A method of manufacturing a light receiving and emitting device, wherein a second conductivity type impurity is diffused in a first conductivity type compound semiconductor substrate, wherein (a) a diffusion prevention film is laminated on the first conductivity type compound semiconductor substrate. And (b) forming a diffusion window in the diffusion prevention film, covering the exposed region of the first conductivity type with a diffusion control film, and diffusing impurities through the diffusion control film to form the second conductivity type. And (c) partially forming the first conductivity type compound semiconductor substrate adjacent to the second conductivity type diffusion region so that a part of the first conductivity type region remains in the vicinity of the substrate end face. The method for manufacturing a light emitting and receiving element, which comprises performing a step of selectively etching. 7. A method of manufacturing a light receiving and emitting device, wherein a second conductivity type impurity is diffused in a first conductivity type compound semiconductor substrate, wherein (a) a diffusion prevention film is laminated on the first conductivity type compound semiconductor substrate. And (b) forming a diffusion window in the diffusion prevention film to expose a region of the first conductivity type, and (c)
A region for making the diffusion depth shallow and a region for making the diffusion depth deep in the exposed region of the first conductivity type are both covered with a diffusion control film,
Moreover, a step of making the thickness of the diffusion control film thick on a region where the diffusion depth is formed shallow and thin on a region where the diffusion depth is formed deep, and (d) diffusing impurities through the diffusion control film. Forming a second diffusion type first diffusion region having a shallow diffusion depth and a second diffusion type second diffusion region having a deep diffusion depth; and (e) a portion of the first conductivity type region in the vicinity of the end face of the substrate. And a step of partially etching the first-conductivity-type compound semiconductor substrate adjacent to the second-conductivity-type diffusion region, so that the remaining light-emitting element remains.