US20140175510A1 - Germanium photodetector and method of fabricating the same - Google Patents
Germanium photodetector and method of fabricating the same Download PDFInfo
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- US20140175510A1 US20140175510A1 US14/194,723 US201414194723A US2014175510A1 US 20140175510 A1 US20140175510 A1 US 20140175510A1 US 201414194723 A US201414194723 A US 201414194723A US 2014175510 A1 US2014175510 A1 US 2014175510A1
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- GNPVGFCGXDBREM-UHFFFAOYSA-N germanium atom Chemical compound [Ge] GNPVGFCGXDBREM-UHFFFAOYSA-N 0.000 title claims abstract description 107
- 229910052732 germanium Inorganic materials 0.000 title claims abstract description 106
- 238000004519 manufacturing process Methods 0.000 title abstract description 12
- 239000000758 substrate Substances 0.000 claims abstract description 44
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims description 17
- 229910052710 silicon Inorganic materials 0.000 claims description 16
- 239000010703 silicon Substances 0.000 claims description 16
- 229910000577 Silicon-germanium Inorganic materials 0.000 claims description 2
- 238000005530 etching Methods 0.000 claims description 2
- 238000000034 method Methods 0.000 abstract description 14
- 239000007789 gas Substances 0.000 description 6
- QUZPNFFHZPRKJD-UHFFFAOYSA-N germane Chemical compound [GeH4] QUZPNFFHZPRKJD-UHFFFAOYSA-N 0.000 description 6
- 229910052986 germanium hydride Inorganic materials 0.000 description 6
- 238000010438 heat treatment Methods 0.000 description 6
- 238000002161 passivation Methods 0.000 description 6
- 238000000137 annealing Methods 0.000 description 5
- MWUXSHHQAYIFBG-UHFFFAOYSA-N Nitric oxide Chemical compound O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 description 4
- 230000007547 defect Effects 0.000 description 4
- 238000000151 deposition Methods 0.000 description 4
- 238000004891 communication Methods 0.000 description 3
- 239000013078 crystal Substances 0.000 description 3
- 239000012535 impurity Substances 0.000 description 3
- 230000003287 optical effect Effects 0.000 description 3
- 239000004065 semiconductor Substances 0.000 description 3
- 238000002441 X-ray diffraction Methods 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 2
- 238000002425 crystallisation Methods 0.000 description 2
- 230000008025 crystallization Effects 0.000 description 2
- 230000008021 deposition Effects 0.000 description 2
- 238000009792 diffusion process Methods 0.000 description 2
- 238000005468 ion implantation Methods 0.000 description 2
- 150000004767 nitrides Chemical class 0.000 description 2
- 229910021420 polycrystalline silicon Inorganic materials 0.000 description 2
- 229920005591 polysilicon Polymers 0.000 description 2
- 239000012495 reaction gas Substances 0.000 description 2
- 238000000038 ultrahigh vacuum chemical vapour deposition Methods 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 1
- 230000006835 compression Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 230000005684 electric field Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000011065 in-situ storage Methods 0.000 description 1
- 239000012212 insulator Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000001451 molecular beam epitaxy Methods 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
- 230000002123 temporal effect Effects 0.000 description 1
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Abstract
Provided is a germanium photodetector having a germanium epitaxial layer formed without using a buffer layer and a method of fabricating the same. In the method, an amorphous germanium layer is formed on a substrate. The amorphous germanium layer is heated up to a high temperature to form a crystallized germanium layer. A germanium epitaxial layer is formed on the crystallized germanium layer.
Description
- This U.S. non-provisional patent application claims priority under 35 U.S.C. §119 of Korean Patent Application No. 10-2008-0105199, filed on Oct. 27, 2008, the entire contents of which are hereby incorporated by reference.
- The present invention disclosed herein relates to a photodetector and a method of fabricating the same, and more particularly, to a germanium photodetector and a method of fabricating the same.
- Recent silicon-based optical communication technology uses germanium in both of the active device and passive device applications. Because the band gap energy (0.67 eV) of the germanium is smaller than the band gap energy (1.12eV) of the silicon, the germanium can detect generic optical communication wavelengths λ of 1.3 μm to 1.6 μm that cannot be detected by the silicon. However, the germanium has a lattice constant difference of 4% from the silicon. Therefore, it is difficult to grow a low-defect germanium epitaxial layer directly on a silicon substrate. There is a method of fabricating a p-i-n detector by forming a SiGe buffer layer between the silicon substrate and the germanium epitaxial layer. However, the buffer layer has many inherent crystal defects, and the buffer layer must be thick enough to grow the germanium epitaxial layer. Therefore, the buffer layer degrades the detector's performance and also imposes many restrictions on the fabrication process. There is a method of forming the germanium epitaxial layer on the silicon substrate through an ultra-high vacuum process of 10−9 torr or less, such as ultra-high vacuum chemical vapor deposition (UHVCVD) or molecular beam epitaxy (MBE), without using the buffer layer. This method, however, requires a high-temperature annealing process of 700° C. or more in order to reduce crystal defects such as dislocations. Thus, due to the high-temperature annealing process, the method is low in productivity and has a limitation in mass production.
- The present invention provides a photodetector with a germanium epitaxial layer and a method of fabricating the same.
- In some embodiments of the present invention, methods of fabricating a germanium photodetector include: forming an amorphous germanium layer on a substrate at a first temperature; crystallizing the amorphous germanium layer while heating from the first temperature to a second temperature; and forming a germanium epitaxial layer on the crystallized germanium layer.
- In some embodiments, the forming of the germanium epitaxial layer on the crystallized germanium layer is performed at the second temperature, or during the heating from the first temperature to the second temperature.
- In other embodiments of the present invention, germanium photodetectors include: a germanium epitaxial layer disposed directly on a substrate;
- a first doped layer on the germanium epitaxial layer; and a second doped layer disposed on the substrate or under the germanium epitaxial layer, the second doped layer having a different conductivity type from the first doped layer.
- The accompanying figures are included to provide a further understanding of the present invention, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the present invention and, together with the description, serve to explain principles of the present invention. In the figures:
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FIGS. 1 to 3 and 6 to 8 are cross-sectional views illustrating a method of fabricating a germanium photodetector according to some exemplary embodiments of the present invention; -
FIG. 4A is a transmission electron microscope (TEM) image of an interface of a germanium epitaxial layer formed on a substrate according to exemplary embodiments of the present invention; -
FIG. 4B is an expanded view of a portion A ofFIG. 4A ; -
FIG. 5 is a graph illustrating the X-ray diffraction characteristics of a germanium epitaxial layer formed on a substrate according to exemplary embodiments of the present invention; -
FIGS. 9 to 13 are cross-sectional views illustrating a method of fabricating a germanium photodetector according to other exemplary embodiments of the present invention; -
FIG. 14 is a graph illustrating the current-voltage characteristics of a germanium photodetector according to exemplary embodiments of the present invention; and -
FIG. 15 is a graph illustrating the bit rate of a germanium photodetector according to exemplary embodiments of the present invention. - Preferred embodiments of the present invention will be described below in more detail with reference to the accompanying drawings. The present invention may, however, be embodied in different forms and should not be constructed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present invention to those skilled in the art.
- It will be understood that when a layer (or film) is referred to as being ‘on’ another layer or substrate, it can be directly on the other layer or substrate, or intervening layers may also be present. Also, though terms like a first, a second, and a third are used to describe various regions and layers in various embodiments of the present invention, the regions and the layers are not limited to these terms. These terms are used only to tell one region or layer from another region or layer.
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FIGS. 1 to 3 and 6 to 8 are cross-sectional views illustrating a method of fabricating a germanium photodetector according to some exemplary embodiments of the present invention. - Referring to
FIG. 1 , a first dopedlayer 110 is formed on asubstrate 100. Thesubstrate 100 may include a semiconductor-based structure with a silicon surface. The semiconductor-based structure may be a silicon layer, a silicon-on-insulator (SOI) layer, or a silicon epitaxial layer based on a semiconductor structure. Thesubstrate 100 may be a substrate where an insulating layer or a conductive layer is formed. In an embodiment, an n-type or p-type first dopedlayer 110 is formed on thesubstrate 100 through an ion implantation or diffusion process. For example, the first dopedlayer 110 may have a doping concentration of about 5×1020/cm3. - Referring to
FIG. 2 , anamorphous germanium layer 120 is formed on the first dopedlayer 110. To this end, for example, GeH4 gas is introduced to thesubstrate 100. Herein, thesubstrate 100 may maintain a low temperature of about 300° C. to about 500° C. under a pressure of about 1 torr to about 300 torr. The GeH4 gas is decomposed into germanium and H2 gas, and the germanium is deposited onto thesubstrate 100 to form a germanium layer with a very small thickness of about 300 nm or less. The very small thickness can be achieved because the deposition rate is low. Due to the low substrate temperature, the germanium layer grows into an amorphous state on thesubstrate 100. - Referring to
FIG. 3 , thesubstrate 100 is heated up to a high temperature of about 600° C. to about 700° C. During the heating process, at least a portion of theamorphous germanium layer 120 may be crystallized to form a crystallizedgermanium layer 121. During or after the heating process, reaction gas GeH4 is introduced onto thesubstrate 100 to form a germaniumepitaxial layer 130. The crystallization and the growth of the germaniumepitaxial layer 130 may be performed under a pressure of about 1 torr to about 300 torr. The resulting germaniumepitaxial layer 130 reduces a stress due to a lattice constant difference with thesubstrate 100, thus making it possible to omit a additional buffer layer or a additional annealing process. Accordingly, the germaniumepitaxial layer 130 deposited on the crystallizedgermanium layer 121 can grow epitaxially due to the homogeneous elements. Consequently, it is possible to reduce lattice defects due to a lattice constant difference between the germaniumepitaxial layer 130 and thesubstrate 100. -
FIG. 4A is a transmission electron microscope (TEM) image of an interface of the germaniumepitaxial layer 130 formed on thesubstrate 100; andFIG. 4B is an expanded view of a portion A ofFIG. 4A . It can be seen fromFIGS. 4A and 4B that thegermanium epitaxial layer 130 has grown to a thickness of about 1.3 μm from the crystallizedgermanium layer 121 that was formed to a thickness of about 0.1 μm on thesubstrate 100. Thegermanium epitaxial layer 130 has a low threading dislocation density of about 2×106/cm2 measured by Secco etching. Most of the germanium atoms were coherently deposited on the silicon atoms of thesubstrate 100. By the threading dislocation, the crystallizedgermanium layer 121 reduces a lattice constant difference (i.e., a lattice mismatch) of about 4% between the silicon and the germanium. -
FIG. 5 is a graph illustrating the X-ray diffraction characteristics of thegermanium epitaxial layer 130 formed on thesubstrate 100. Apeak 101 ofFIG. 5 represents a diffraction crystal plane of thegermanium epitaxial layer 130 formed on thesubstrate 100. It can be seen fromFIG. 5 that thegermanium epitaxial layer 130 has grown into an epitaxial crystalline structure without other polycrystalline structures. - Referring to
FIG. 6 , a second dopedlayer 140 is formed on thegermanium epitaxial layer 130. In an embodiment, the second dopedlayer 140 may be formed by introducing n-type or p-type impurity elements to thegermanium epitaxial layer 130. In another embodiment, the second dopedlayer 140 may be formed by depositing n-type or p-type doped silicon or polysilicon on thegermanium epitaxial layer 130. For example, the second dopedlayer 140 may have a doping concentration of about 1×1019/cm3. The seconddoped layer 140 has a different conductivity type from the first dopedlayer 110, thus forming a p-i-n detector. - Referring to
FIGS. 7 and 8 , the crystallizedgermanium layer 121, thegermanium epitaxial layer 130, and the second dopedlayer 140 are anisotropically etched and patterned to expose the first dopedlayer 110. An insulatingpassivation layer 160 is formed on the resulting structure. The insulatingpassivation layer 160 may be formed of an oxide, a nitride, or a nitric oxide. A portion of the insulatingpassivation layer 160 is etched to expose the first dopedlayer 110 and the second dopedlayer 140. Anelectrode 150 is formed on the exposed portion. -
FIGS. 9 to 13 are cross-sectional views illustrating a method of fabricating a germanium photodetector according to other exemplary embodiments of the present invention. - The present embodiments of
FIGS. 9 to 13 are similar to the embodiments ofFIGS. 1 to 3 and 6 to 8, with the exception of a difference in the forming method of the first doped layer. Thus, a description of the overlapping technical features will be omitted for conciseness. - Referring to
FIG. 9 , an amorphous germanium first dopedlayer 220 is formed on asubstrate 200. To this end, for example, GeH4 gas is introduced to thesubstrate 200. Herein, thesubstrate 200 may maintain a low temperature of about 300° C. to about 500° C. under a pressure of about 1 torr to about 300 torr. The GeH4 gas is decomposed into germanium and H2 gas, and the germanium is deposited onto thesubstrate 200 to form a germanium layer with a very small thickness of about 300 nm or less. The very small thickness can be achieved because the deposition rate is low. Due to the low substrate temperature, the germanium layer grows into an amorphous state on thesubstrate 200. The amorphous germanium layer is doped with n-type or p-type impurities in situ through an ion implantation or diffusion process during the formation thereof, to form the amorphous germanium first dopedlayer 220. For example, the first dopedlayer 220 may have a doping concentration of about 5×1020/cm3. - Referring to
FIG. 10 , thesubstrate 200 and amorphous germanium first dopedlayer 220 are heated up to a high temperature of about 600° C. to about 700° C. During the heating process, at least a portion of the amorphous germanium first dopedlayer 220 may be crystallized to form a crystallized germanium first dopedlayer 221. During or after the heating process, reaction gas GeH4 is introduced onto thesubstrate 200 to form agermanium epitaxial layer 230. The crystallization and the growth of thegermanium epitaxial layer 230 may be performed under a pressure of about 1 torr to about 300 torr. The resultinggermanium epitaxial layer 230 reduces a stress due to a lattice constant difference with thesubstrate 200, thus making it possible to omit a additional buffer layer or a additional annealing process. Accordingly, thegermanium epitaxial layer 230 deposited on the crystallized germanium first dopedlayer 221 can grow epitaxially due to the homogeneous elements. Consequently, it is possible to reduce lattice defects due to a lattice constant difference between thegermanium epitaxial layer 230 and thesubstrate 200. - Referring to
FIG. 11 , a second dopedlayer 240 is formed on thegermanium epitaxial layer 230. In an embodiment, the second dopedlayer 240 may be formed by introducing n-type or p-type impurity elements to thegermanium epitaxial layer 230. In another embodiment, the second dopedlayer 240 may be formed by depositing n-type or p-type doped silicon or polysilicon on thegermanium epitaxial layer 230. For example, the second dopedlayer 240 may have a doping concentration of about 1×1019/cm3. The seconddoped layer 240 has a different conductivity type from the crystallized germanium first dopedlayer 221, thus forming a p-i-n detector. - Referring to
FIGS. 12 and 13 , the crystallized germanium first dopedlayer 221, thegermanium epitaxial layer 230, and the second dopedlayer 240 are anisotropically etched and patterned to expose the crystallized germanium first dopedlayer 221. An insulatingpassivation layer 260 is formed on the resulting structure. The insulatingpassivation layer 260 may be formed of an oxide, a nitride, or a nitric oxide. A portion of the insulatingpassivation layer 260 is etched to expose the crystallized germanium first dopedlayer 221 and the second dopedlayer 240. Anelectrode 250 is formed on the exposed portion. -
FIG. 14 is a graph illustrating the current-voltage characteristics of a germanium photodetector according to exemplary embodiments of the present invention. An photocurrent with a responsivity of about 0.47 A/W is flat over a wide range of reverse bias voltage, and a leakage current is about 30 nA at about −0.5 V. Also, a nearly full DC responsivity was obtained even at 0 V. This means that an electric field is formed sufficiently to the extent that it is formed in a depletion region even without bias. Up to an optical power of about 5 mW, no compression of a DC photocurrent was observed. -
FIG. 15 is a graph illustrating the bit rate of a germanium photodetector according to exemplary embodiments of the present invention. The speed of the germanium photodetector was measured using an impulse response measurement for the detector with diameter of about 20 μm to about 40 μm. Mode-locked pulses of a Digital Communication Analyzer with a center wavelength of about 1550 nm are coupled into the detector of −1 V, −2 V and −3 V. The shape of an temporal response of the detector was mostly Gaussian with a hillock-shaped at the tail. Fourier transform of the measured pulse was performed to obtain the frequency spectrum ofFIG. 15 . A resulting bandwidth of about 3-dB for 35 GHz shows that the detector can afford a bit rate up to 50 Gb/s. - As described above, the present invention forms a germanium epitaxial layer in a low vacuum without the use of a buffer layer and an annealing process, thereby making it possible to provide a germanium photodetector that is relatively low in substrate/process costs.
- The above-disclosed subject matter is to be considered illustrative, and not restrictive, and the appended claims are intended to cover all such modifications, enhancements, and other embodiments, which fall within the true spirit and scope of the present invention. Thus, to the maximum extent allowed by law, the scope of the present invention is to be determined by the broadest permissible interpretation of the following claims and their equivalents, and shall not be restricted or limited by the foregoing detailed description.
Claims (5)
1.-7. (canceled)
8. A germanium photodetector comprising:
a germanium epitaxial layer disposed directly on a silicon substrate;
a first doped layer on the germanium epitaxial layer; and
a second doped layer disposed under the germanium epitaxial layer, the second doped layer having a different conductivity type from the first doped layer.
9. The germanium photodetector of claim 8 , wherein the germanium epitaxial layer has a threading dislocation density of about 2×106/cm2 or less measured by Secco etching.
10. The germanium photodetector of claim 8 , wherein the germanium photodetector has a leakage current of about 100 nA or less at about −1.0 V.
11. A germanium photodetector comprising:
a germanium epitaxial layer disposed on a silicon substrate;
a first doped layer on the germanium epitaxial layer; and
a second doped layer disposed under the germanium epitaxial layer, the second doped layer having a different conductivity type from the first doped layer
wherein an interface between the silicon substrate and the germanium epitaxial layer is free from a SiGe buffer.
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US12/404,275 US8698271B2 (en) | 2008-10-27 | 2009-03-13 | Germanium photodetector and method of fabricating the same |
US14/194,723 US20140175510A1 (en) | 2008-10-27 | 2014-03-01 | Germanium photodetector and method of fabricating the same |
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Family Cites Families (15)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP3907726B2 (en) | 1995-12-09 | 2007-04-18 | 株式会社半導体エネルギー研究所 | Method for manufacturing microcrystalline silicon film, method for manufacturing semiconductor device, and method for manufacturing photoelectric conversion device |
US6130144A (en) * | 1997-01-02 | 2000-10-10 | Texas Instruments Incorporated | Method for making very shallow junctions in silicon devices |
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US6693298B2 (en) | 2001-07-20 | 2004-02-17 | Motorola, Inc. | Structure and method for fabricating epitaxial semiconductor on insulator (SOI) structures and devices utilizing the formation of a compliant substrate for materials used to form same |
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US7288825B2 (en) * | 2002-12-18 | 2007-10-30 | Noble Peak Vision Corp. | Low-noise semiconductor photodetectors |
US7682947B2 (en) * | 2003-03-13 | 2010-03-23 | Asm America, Inc. | Epitaxial semiconductor deposition methods and structures |
TWI221001B (en) | 2003-07-28 | 2004-09-11 | Univ Nat Chiao Tung | A method for growing a GaAs epitaxial layer on Ge/GeSi/Si substrate |
US7259084B2 (en) | 2003-07-28 | 2007-08-21 | National Chiao-Tung University | Growth of GaAs epitaxial layers on Si substrate by using a novel GeSi buffer layer |
US7138697B2 (en) | 2004-02-24 | 2006-11-21 | International Business Machines Corporation | Structure for and method of fabricating a high-speed CMOS-compatible Ge-on-insulator photodetector |
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US7785982B2 (en) * | 2007-01-05 | 2010-08-31 | International Business Machines Corporation | Structures containing electrodeposited germanium and methods for their fabrication |
-
2008
- 2008-10-27 KR KR1020080105199A patent/KR101000941B1/en active IP Right Grant
-
2009
- 2009-03-13 US US12/404,275 patent/US8698271B2/en active Active
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2014
- 2014-03-01 US US14/194,723 patent/US20140175510A1/en not_active Abandoned
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Also Published As
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KR101000941B1 (en) | 2010-12-13 |
KR20100046381A (en) | 2010-05-07 |
US8698271B2 (en) | 2014-04-15 |
US20100102412A1 (en) | 2010-04-29 |
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