CN111785791A - Ge photoelectric detector and preparation method thereof - Google Patents

Ge photoelectric detector and preparation method thereof Download PDF

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Publication number
CN111785791A
CN111785791A CN202010718274.XA CN202010718274A CN111785791A CN 111785791 A CN111785791 A CN 111785791A CN 202010718274 A CN202010718274 A CN 202010718274A CN 111785791 A CN111785791 A CN 111785791A
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layer
type doped
contact region
heat source
doped contact
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方青
张馨丹
邵瑶
胡鹤鸣
顾苗苗
陈华
张志群
陈晓峰
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China Online Shanghai Energy Internet Research Institute Co ltd
Harbin Zhongda Electronic Co Ltd
Kunming University of Science and Technology
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China Online Shanghai Energy Internet Research Institute Co ltd
Harbin Zhongda Electronic Co Ltd
Kunming University of Science and Technology
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    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/08—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof in which radiation controls flow of current through the device, e.g. photoresistors
    • H01L31/10—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof in which radiation controls flow of current through the device, e.g. photoresistors characterised by potential barriers, e.g. phototransistors
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    • H01L31/102—Devices sensitive to infrared, visible or ultraviolet radiation characterised by only one potential barrier
    • H01L31/105—Devices sensitive to infrared, visible or ultraviolet radiation characterised by only one potential barrier the potential barrier being of the PIN type
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/18—Processes or apparatus specially adapted for the manufacture or treatment of these devices or of parts thereof
    • H01L31/1804—Processes or apparatus specially adapted for the manufacture or treatment of these devices or of parts thereof comprising only elements of Group IV of the Periodic Table
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Abstract

The invention provides a Ge photoelectric detector and a preparation method thereof, wherein the Ge photoelectric detector comprises a heat source layer and further comprises a heat conduction layer; the Ge photoelectric detector is characterized in that a heat source layer with high resistance is used as a heat source to raise the temperature of the Ge absorption layer, so that the forbidden bandwidth of the Ge absorption layer is reduced, photons with energy lower than that of the forbidden bandwidth of the original Ge absorption layer are absorbed to increase the absorption coefficient of the Ge absorption layer, the detection range of the Ge photoelectric detector is extended to enlarge the application range, and a heat source generated by the heat source layer is effectively transmitted to the Ge absorption layer through a heat conduction layer with high heat conductivity between the Ge absorption layer and the heat source layer, so that the responsivity of the Ge photoelectric detector is effectively adjusted; therefore, the invention can provide a method which has simple preparation process and can effectively improve the absorption coefficient of the Ge photoelectric detector under the long wavelength condition so as to expand the detection range and the application range of the Ge photoelectric detector.

Description

Ge photoelectric detector and preparation method thereof
Technical Field
The invention belongs to the technical field of photoelectrons, and relates to a Ge photoelectric detector and a preparation method thereof.
Background
The photoelectric detector has wide application in various fields of military and national economy. The silicon-based Ge photoelectric detector is compatible with a CMOS (complementary metal oxide semiconductor) process and convenient to integrate, and has wide application in the fields of optical communication, optical interconnection, optical sensing and the like. Compared with a surface incidence type photoelectric detector, the waveguide type photoelectric detector can avoid the problem that the speed and the quantum efficiency of the photoelectric detector are mutually restricted, can be integrated with a waveguide optical circuit, is easier to realize high speed and high responsivity, and is one of core devices for realizing high speed optical communication and optical interconnection chips. However, the absorption coefficient of the Ge material drops sharply at wavelengths longer than 1.55 μm, which makes the Ge photodetector unable to meet the application requirements of the L-band (long-wavelength band, wavelength range 1.56 μm to 1.63 μm) or even the U-band (ultra-long-wavelength band, wavelength range 1.63 μm to 1.68 μm).
In order to solve the problem that the Ge material has a low absorption coefficient at a long wavelength, in the prior art, a Sn material is usually introduced into the Ge material to extend the detection range of the Ge photodetector, however, the introduction of the Sn material increases the difficulty of the process, and at the same time, the introduction of the Sn material also reduces the thermal stability of the Ge material, thereby limiting the practical application.
Therefore, it is necessary to provide a novel Ge photodetector and a method for manufacturing the same.
Disclosure of Invention
In view of the above-mentioned drawbacks of the prior art, an object of the present invention is to provide a Ge photodetector and a method for manufacturing the same, which are used to solve the problem of low absorption coefficient of the Ge photodetector in the prior art under a long wavelength condition.
To achieve the above and other related objects, the present invention provides a Ge photodetector including:
the Si waveguide comprises a bottom Si layer, an oxygen burying layer and a top Si layer which are sequentially overlapped; the top Si layer comprises a P-type doped contact region, an I-type region and an N-type doped contact region which are sequentially arranged in the horizontal direction;
a Ge absorbing layer on the I-type region;
the passivation layer covers the P-type doped contact region, the N-type doped contact region and the Ge absorption layer;
a heat source layer located above the Ge absorbing layer;
and the metal electrode penetrates through the passivation layer and is in contact with the P-type doped contact region and the N-type doped contact region.
Optionally, the thickness D of the passivation layer between the heat source layer and the Ge absorption layer ranges from D ≧ 0.5 μm.
Optionally, the thermal source layer comprises one or a combination of a TiN layer and a TaN layer.
Optionally, a thermally conductive layer is further included between the Ge absorbing layer and the heat source layer, and the thermally conductive layer has a thermal conductivity greater than the passivation layer.
Optionally, opposite sides of the thermally conductive layer are in contact with the Ge absorption layer and the heat source layer, respectively, wherein the thermally conductive layer comprises an AlN layer.
The invention also provides a preparation method of the Ge photoelectric detector, which comprises the following steps:
providing an SOI substrate;
carrying out photoetching to form a Si waveguide, wherein the Si waveguide comprises a bottom Si layer, an oxygen burying layer and a top Si layer which are sequentially superposed;
forming a P-type doped contact region and an N-type doped contact region in the top Si layer respectively by ion implantation so as to form the P-type doped contact region, the I-type region and the N-type doped contact region which are sequentially arranged in the horizontal direction in the top Si layer;
forming a Ge absorption layer on the I-type region;
forming a passivation layer, wherein the passivation layer covers the P-type doped contact region, the N-type doped contact region and the Ge absorption layer;
forming a heat source layer, the heat source layer being located above the Ge absorbing layer;
and forming a metal electrode, wherein the metal electrode penetrates through the passivation layer and is in contact with the P-type doped contact region and the N-type doped contact region.
Optionally, after forming the Ge-absorbing layer and before forming the metal electrode, the method comprises the steps of:
forming a first passivation layer to cover the P-type doped contact region, the N-type doped contact region and the Ge absorption layer;
forming a heat source layer over the Ge absorbing layer;
forming a second passivation layer covering the heat source layer;
and forming a groove penetrating through the second passivation layer and the first passivation layer, and filling the groove to form a metal electrode in contact with the P-type doped contact region and the N-type doped contact region.
Optionally, the thickness D of the first passivation layer between the heat source layer and the Ge absorption layer ranges from D to 0.5 μm, wherein the heat source layer comprises one or a combination of a TiN layer and a TaN layer; the first passivation layer comprises SiO2A layer; the second passivation layer comprises SiO2And (3) a layer.
Optionally, after forming the Ge-absorbing layer and before forming the metal electrode, the method comprises the steps of:
forming a first passivation layer to cover the P-type doped contact region, the N-type doped contact region and the Ge absorption layer, and flattening to expose the Ge absorption layer;
forming a heat conduction layer and a heat source layer above the Ge absorption layer in sequence;
forming a second passivation layer wrapping the heat source layer and the heat conduction layer;
and forming a groove penetrating through the second passivation layer and the first passivation layer, and filling the groove to form a metal electrode in contact with the P-type doped contact region and the N-type doped contact region.
Optionally, two opposite surfaces of the heat conduction layer are respectively in contact with the Ge absorption layer and the heat source layer, the range of the thickness H of the heat conduction layer includes that H is greater than or equal to 0.5 μm, wherein the heat source layer includes one or a combination of a TiN layer and a TaN layer; the thermally conductive layer includes an AlN layer; the first passivation layer comprises SiO2A layer; the second passivation layer comprises SiO2And (3) a layer.
As described above, according to the Ge photodetector and the preparation method thereof of the present invention, the heat source layer with high resistance is used as the heat source to raise the temperature of the Ge absorption layer, so as to reduce the forbidden bandwidth of the Ge absorption layer, thereby enabling photons with energy lower than that of the forbidden bandwidth of the original Ge absorption layer to be absorbed, so as to increase the absorption coefficient of the Ge absorption layer, and extend the detection range of the Ge photodetector, so as to expand the application range; furthermore, the heat source generated by the heat source layer can be effectively transferred to the Ge absorption layer through the heat conduction layer with higher heat conductivity between the Ge absorption layer and the heat source layer, so that the responsivity of the Ge photoelectric detector is effectively adjusted; therefore, the invention can provide a method which has simple preparation process and can effectively improve the absorption coefficient of the Ge photoelectric detector under the long wavelength condition so as to expand the detection range and the application range of the Ge photoelectric detector.
Drawings
Fig. 1 shows a schematic process flow diagram for fabricating a Ge photodetector according to the present invention.
Fig. 2 to 5 are schematic structural views showing steps of fabricating a Ge photodetector according to the first embodiment.
Fig. 6 to 9 show schematic structural views of steps of manufacturing another Ge photodetector according to the second embodiment.
Description of the element reference numerals
110. 210 Si waveguide
111. 211 bottom Si layer
112. 212 buried oxide layer
113. 213 top Si layer
1131. 2131P type doped contact region
1132. 2132 type I region
1133. 2133N type doped contact region
120. 220 Ge absorbing layer
130. 230 first passivation layer
140. 240 heat source layer
150. 250 second passivation layer
160. 260 metal electrode
300 Heat conducting layer
D. H thickness
Detailed Description
The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention.
Please refer to fig. 1 to 9. It should be noted that the drawings provided in the present embodiment are only for illustrating the basic idea of the present invention, and the components related to the present invention are only shown in the drawings rather than drawn according to the number, shape and size of the components in actual implementation, and the type, quantity and proportion of the components in actual implementation may be changed freely, and the layout of the components may be more complicated.
Example one
Referring to fig. 5, the present embodiment provides a Ge photodetector including a Si waveguide 110, a Ge absorption layer 120, a first passivation layer 130, a heat source layer 140, a second passivation layer 150, and a metal electrode 160. The Si waveguide 110 includes a bottom Si layer 111, a buried oxide layer 112, and a top Si layer 113 stacked in sequence; wherein the top Si layer 113 includes a P-type doped contact region 1131, an I-type region 1132 and an N-type doped contact region 1133 sequentially arranged in a horizontal direction; the Ge absorption layer 120 is located on the I-type region 1132; the first passivation layer 130 covers the P-doped contact region 1131, the N-doped contact region 1133 and the Ge absorption layer 120; the thermal source layer 140 is located above the Ge absorption layer 120; the second passivation layer 150 encapsulates the heat source layer 140; the metal electrode 160 penetrates through the first passivation layer 130 and the second passivation layer 150, and contacts the P-type doped contact region 1131 and the N-type doped contact region 1133.
In this embodiment, the heat source layer 140 with a high resistance is used as a heat source, so that the temperature of the Ge absorption layer 120 can be raised, the forbidden bandwidth of the Ge absorption layer 120 is reduced, photons with energy lower than that of the original Ge absorption layer are absorbed, the absorption coefficient of the Ge absorption layer 120 is increased, the extension of the detection range of the Ge photodetector is realized, and the application range is expanded.
Referring to fig. 1, the present embodiment provides a process flow diagram for manufacturing the Ge photodetector, wherein fig. 2 to 5 illustrate structural schematic diagrams presented in steps of manufacturing the Ge photodetector. It should be noted that the method for manufacturing the Ge photodetector is not limited to this.
Referring to fig. 2, an SOI substrate is first provided.
Specifically, the thickness of the SOI substrate may include 150nm to 250nm, such as 200nm, 220nm, etc., and the specific thickness and size of the SOI substrate may be selected according to the need, which is not limited herein. Wherein, the SOI substrate can be purchased directly or prepared according to the need, which is not limited herein.
Next, photolithography is performed to form a Si waveguide 110, and the Si waveguide 110 includes a bottom Si layer 111, a buried oxide layer 112, and a top Si layer 113, which are sequentially stacked. The specific process and shape of the Si waveguide 110 are not limited herein, and may be selected according to the requirement.
Next, a P-type doped contact region 1131 and an N-type doped contact region 1133 are respectively formed in the top Si layer 113 by ion implantation, so as to form the P-type doped contact region 1131, the I-type region 1132 and the N-type doped contact region 1133 sequentially arranged in the horizontal direction in the top Si layer 113.
Specifically, the steps of forming the P-type doped contact 1131 and the N-type doped contact 1133 may include:
forming a first SiO on the surface of the top Si layer 113 using a deposition process, such as CVD2A layer (not shown) to pass through the first SiO2The layer is used as a protective layer for ion implantation;
etching away the first SiO in the region corresponding to the P-type doped contact region 1131 by using a first mask (not shown) and an anisotropic etching process2A layer;
performing ion implantation to form the P-type doped region 1131, and etching away the first SiO2 layer;
then, the deposition process is carried out again to form the second SiO2A layer (not shown) to pass through the second SiO2The layer is used as a protective layer for ion implantation;
etching away the second SiO in the region corresponding to the N-type doped contact region 1133 by using a second mask (not shown) and an anisotropic etching process2A layer;
performing ion implantation to form the N-type doped region 1133, and etching away the second SiO2And (3) a layer.
The type, amount and energy of the ion implantation used in forming the P-type doped contact region 1131 and the N-type doped region 1133 can be selected according to the requirement, and are not limited herein. In this embodiment, through the ion implantation process, the P-type doped contact region 1131, the I-type region 1132 and the N-type doped contact region 1133 sequentially arranged in the horizontal direction may be formed in the top Si layer 113, i.e. a P-I-N structure is formed.
Next, referring to fig. 3, a Ge absorption layer 120 is formed on the I-type region 1132.
Specifically, the Ge absorption layer 120 with a thickness of 300nm to 500nm, such as 350nm, 400nm, 450nm, and the like, may be formed on the I-type region 1132 by using a selective epitaxial growth method.
Next, a passivation layer is formed covering the P-doped contact region 1131, the N-doped contact region 1133 and the Ge absorption layer 120.
Specifically, referring to fig. 3, in the present embodiment, after the Ge absorption layer 120 is formed, a first passivation layer 130 is formed, and the first passivation layer 130 covers the P-type doped contact region 1131, the N-type doped contact region 1133 and the Ge absorption layer 120, and a thickness D is provided between the surface of the first passivation layer 130 and the Ge absorption layer 120, wherein the thickness D preferably ranges from D ≧ 0.5 μm, such as 1.0 μm, 1.5 μm, 2 μm, and the like, so as to improve the light absorption performance of the Ge absorption layer 120 and reduce the influence of a subsequently formed heat source layer 140 on the light absorption performance of the Ge absorption layer 120.
Next, referring to fig. 4, the heat source layer 140 is formed, which is located above the Ge absorption layer 120.
Specifically, the heat source layer 140 may be formed by a CVD method and then patterned. The thermal source layer 140 is a material layer with a high resistance, so that when the thermal source layer 140 is connected to a power supply (not shown), the thermal source layer 140 can be used as a heat source to transmit heat to the Ge absorption layer 120, and the temperature of the Ge absorption layer 120 is raised, so that the forbidden bandwidth of the Ge absorption layer 120 is reduced, and photons with energy lower than that of the original Ge absorption layer are absorbed, so as to increase the absorption coefficient of the Ge absorption layer 120, and extend the Ge photodetector detection range, so as to expand the application range.
By way of example, the thermal source layer 140 may include one or a combination of a TiN layer and a TaN layer, but is not limited thereto.
As an example, after the heat source layer 140 is formed, a step of forming a second passivation layer 150 covering the heat source layer 140 is further included.
Specifically, in the embodiment, the second passivation layer 150 is preferably provided to protect the heat source layer 140 through the second passivation layer 150, but is not limited thereto. The second passivation layer 150 may not be formed for simplification of the process, and is not limited herein.
As an example, the first passivation layer 130 and the second passivation layer 150 may be made of the same material, such as SiO2The first passivation layer 130 and the second passivation layer 150 may be made of different materials.
Finally, referring to fig. 5, a metal electrode 160 is formed, wherein the metal electrode 160 penetrates through the second passivation layer 150 and the first passivation layer 130, and contacts the P-type doped contact 1131 and the N-type doped contact 1132.
Specifically, photolithography may be used to form a trench (not shown) penetrating through the second passivation layer 150 and the first passivation layer 130, and the trench is filled with a metal, such as a Cr/Au layer formed by electron beam evaporation, to form the metal electrode 160 contacting the P-type doped contact region 1131 and the N-type doped contact region 1133, and the preparation and material selection of the metal electrode 160 are not limited herein.
Example two
To further introduce the concept of the present invention, the present embodiment further provides a Ge photodetector having a different structure and a different manufacturing method from those of the first embodiment, wherein the differences between the first embodiment and the second embodiment are mainly as follows: the Ge photodetector of this embodiment further includes a heat conducting layer located between the Ge absorption layer and the heat source layer, so that the heat source generated by the heat source layer is effectively transferred to the Ge absorption layer through the heat conducting layer with higher thermal conductivity, thereby further effectively adjusting the responsivity of the Ge photodetector, improving the absorption coefficient of the Ge photodetector under a long wavelength condition, and expanding the detection range and application range of the Ge photodetector.
In the following, the present embodiment will be described in detail, wherein reference may be made to the first embodiment regarding the preparation, structure, material, and the like of the Ge photodetector.
Referring to fig. 9, the present embodiment provides a Ge photodetector including a Si waveguide 210, a Ge absorption layer 220, a first passivation layer 230, a heat source layer 240, a thermally conductive layer 300, a second passivation layer 250, and a metal electrode 260. Wherein the Si waveguide 210 comprises a bottom Si layer 211, a buried oxide layer 212, and a top Si layer 213 stacked in sequence; the top Si layer 213 includes a P-type doped contact region 2131, an I-type region 2132, and an N-type doped contact region 2133, which are sequentially arranged in a horizontal direction; the Ge absorption layer 220 is located on the I-type region 2132; the first passivation layer 230 covers the P-type doped contact region 2131 and the N-type doped contact region 2133 and covers the Ge absorption layer 220; the heat conduction layer 300 and the heat source layer 240 are sequentially located above the Ge absorption layer 220; the second passivation layer 250 encapsulates the heat source layer 240 and the heat conducting layer 300; the metal electrode 260 penetrates through the first passivation layer 230 and the second passivation layer 250, and contacts the P-type doped contact area 2131 and the N-type doped contact area 2133.
Specifically, referring to fig. 7 to 9, in the present embodiment, after the Ge absorption layer 220 is formed and before the metal electrode 260 is formed, the following steps are included:
forming the first passivation layer 230, wherein the first passivation layer 230 covers the P-type doped contact region 2131, the N-type doped contact region 2133 and the Ge absorption layer 220, and then performing planarization, such as a CMP process, to expose the Ge absorption layer 220;
then, the heat conducting layer 300 and the heat source layer 240 are sequentially formed above the Ge absorption layer 220;
next, forming a second passivation layer 250 covering the heat source layer 240 and the heat conduction layer 300;
finally, a trench (not shown) is formed through the second passivation layer 250 and the first passivation layer 230 and filled to form the metal electrode 260 in contact with the P-type doped contact area 2131 and the N-type doped contact area 2133.
Specifically, the heat conducting layer 300 is a material layer with higher thermal conductivity, and the thermal conductivity of the heat conducting layer 300 is greater than that of the passivation layer, that is, the thermal conductivity of the heat conducting layer 300 is greater than that of the first passivation layer 230 (1.38W/mK), so that the heat source generated by the heat source layer 240 can be effectively transferred to the Ge absorption layer 220 through the heat conducting layer 300 with higher thermal conductivity, thereby further effectively adjusting the responsivity of the Ge photodetector, and improving the absorption coefficient of the Ge photodetector under a long wavelength condition, so as to expand the detection range and application range of the Ge photodetector.
For example, two opposite surfaces of the heat conducting layer 300 are preferably in contact with the Ge absorption layer 220 and the heat source layer 240 respectively, so as to further improve the heat transfer performance and reduce the heat loss, but not limited thereto, the heat conducting layer 300 may be in contact with only the heat source layer 240 or the Ge absorption layer 220 or located between the heat source layer 240 and the Ge absorption layer 220, and is not in contact with the heat source layer 240 and the Ge absorption layer 220.
By way of example, the thickness H of the thermally conductive layer 300 preferably includes H ≧ 0.5 μm, such as 1.0 μm, 1.5 μm, 2 μm, and the like, to improve the light absorption properties of the Ge absorbing layer 220 and reduce the influence of the thermal source layer 240 on the light absorption properties of the Ge absorbing layer 220.
The thermally conductive layer 300 includes, by way of example and not limitation, an AlN layer.
By way of example, the thermal source layer 240 preferably includes one or a combination of a TiN layer and a TaN layer, but is not limited thereto.
As an example, the first passivation layer 230 includes SiO2A layer; the second passivation layer 250 includes SiO2In another embodiment, the second passivation layer 250 may not be included to reduce the process complexity, and the materials of the first passivation layer 230 and the second passivation layer 250 are not limited thereto, and may also be different materials.
In summary, according to the Ge photodetector and the preparation method thereof provided by the invention, the heat source layer with high resistance is used as the heat source to raise the temperature of the Ge absorption layer, so that the forbidden bandwidth of the Ge absorption layer is reduced, and photons with energy lower than that of the forbidden bandwidth of the original Ge absorption layer are absorbed, so that the absorption coefficient of the Ge absorption layer is increased, the extension of the detection range of the Ge photodetector is realized, and the application range is expanded; furthermore, the heat source generated by the heat source layer can be effectively transferred to the Ge absorption layer through the heat conduction layer with higher heat conductivity between the Ge absorption layer and the heat source layer, so that the responsivity of the Ge photoelectric detector is effectively adjusted; therefore, the invention can provide a method which has simple preparation process and can effectively improve the absorption coefficient of the Ge photoelectric detector under the long wavelength condition so as to expand the detection range and the application range of the Ge photoelectric detector.
The foregoing embodiments are merely illustrative of the principles and utilities of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which can be made by those skilled in the art without departing from the spirit and technical spirit of the present invention be covered by the claims of the present invention.

Claims (10)

1. A Ge photodetector, comprising:
the Si waveguide comprises a bottom Si layer, an oxygen burying layer and a top Si layer which are sequentially overlapped; the top Si layer comprises a P-type doped contact region, an I-type region and an N-type doped contact region which are sequentially arranged in the horizontal direction;
a Ge absorbing layer on the I-type region;
the passivation layer covers the P-type doped contact region, the N-type doped contact region and the Ge absorption layer;
a heat source layer located above the Ge absorbing layer;
and the metal electrode penetrates through the passivation layer and is in contact with the P-type doped contact region and the N-type doped contact region.
2. The Ge photodetector of claim 1, wherein: the range of the thickness D of the passivation layer between the heat source layer and the Ge absorption layer comprises that D is more than or equal to 0.5 mu m.
3. The Ge photodetector of claim 1, wherein: the heat source layer includes one or a combination of a TiN layer and a TaN layer.
4. The Ge photodetector of claim 1, wherein: the heat source layer is located between the Ge absorption layer and the heat source layer, and the heat conduction layer is larger than the passivation layer in heat conductivity.
5. The Ge photodetector of claim 4, wherein: and two opposite surfaces of the heat conduction layer are respectively contacted with the Ge absorption layer and the heat source layer, wherein the heat conduction layer comprises an AlN layer.
6. A preparation method of a Ge photoelectric detector is characterized by comprising the following steps:
providing an SOI substrate;
carrying out photoetching to form a Si waveguide, wherein the Si waveguide comprises a bottom Si layer, an oxygen burying layer and a top Si layer which are sequentially superposed; forming a P-type doped contact region and an N-type doped contact region in the top Si layer respectively by ion implantation so as to form the P-type doped contact region, the I-type region and the N-type doped contact region which are sequentially arranged in the horizontal direction in the top Si layer;
forming a Ge absorption layer on the I-type region;
forming a passivation layer, wherein the passivation layer covers the P-type doped contact region, the N-type doped contact region and the Ge absorption layer;
forming a heat source layer, the heat source layer being located above the Ge absorbing layer;
and forming a metal electrode, wherein the metal electrode penetrates through the passivation layer and is in contact with the P-type doped contact region and the N-type doped contact region.
7. The method of fabricating a Ge photodetector as claimed in claim 6, characterized by: after forming the Ge absorbing layer and before forming the metal electrode, the method comprises the following steps:
forming a first passivation layer to cover the P-type doped contact region, the N-type doped contact region and the Ge absorption layer;
forming a heat source layer over the Ge absorbing layer;
forming a second passivation layer covering the heat source layer;
and forming a groove penetrating through the second passivation layer and the first passivation layer, and filling the groove to form a metal electrode in contact with the P-type doped contact region and the N-type doped contact region.
8. The method of fabricating a Ge photodetector as claimed in claim 7, characterized by: the range of the thickness D of the first passivation layer between the heat source layer and the Ge absorption layer comprises that D is more than or equal to 0.5 mu m, wherein the heat source layer comprises one or a combination of a TiN layer and a TaN layer; the first passivation layer comprises SiO2A layer; the second passivation layer comprises SiO2And (3) a layer.
9. The method of fabricating a Ge photodetector as claimed in claim 6, characterized by: after forming the Ge absorbing layer and before forming the metal electrode, the method comprises the following steps:
forming a first passivation layer to cover the P-type doped contact region, the N-type doped contact region and the Ge absorption layer, and flattening to expose the Ge absorption layer;
forming a heat conduction layer and a heat source layer above the Ge absorption layer in sequence;
forming a second passivation layer wrapping the heat source layer and the heat conduction layer;
and forming a groove penetrating through the second passivation layer and the first passivation layer, and filling the groove to form a metal electrode in contact with the P-type doped contact region and the N-type doped contact region.
10. The method of fabricating a Ge photodetector as claimed in claim 9, characterized by: the two opposite surfaces of the heat conduction layer are respectively contacted with the Ge absorption layer and the heat source layer, the thickness H of the heat conduction layer is more than or equal to 0.5 mu m, and the heat source layer comprises one or a combination of a TiN layer and a TaN layer; the thermally conductive layer includes an AlN layer; the first passivation layer comprises SiO2A layer; the second passivation layer comprises SiO2And (3) a layer.
CN202010718274.XA 2020-07-23 2020-07-23 Ge photoelectric detector and preparation method thereof Pending CN111785791A (en)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112382681A (en) * 2020-11-02 2021-02-19 联合微电子中心有限责任公司 Semiconductor device and method of forming the same
CN113035982A (en) * 2021-03-03 2021-06-25 中国电子科技集团公司第三十八研究所 All-silicon-doped multi-junction electric field enhanced germanium optical waveguide detector

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112382681A (en) * 2020-11-02 2021-02-19 联合微电子中心有限责任公司 Semiconductor device and method of forming the same
CN113035982A (en) * 2021-03-03 2021-06-25 中国电子科技集团公司第三十八研究所 All-silicon-doped multi-junction electric field enhanced germanium optical waveguide detector

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