CN115966598A - Preparation method and device of enhanced diamond field effect transistor - Google Patents
Preparation method and device of enhanced diamond field effect transistor Download PDFInfo
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- CN115966598A CN115966598A CN202211691889.3A CN202211691889A CN115966598A CN 115966598 A CN115966598 A CN 115966598A CN 202211691889 A CN202211691889 A CN 202211691889A CN 115966598 A CN115966598 A CN 115966598A
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Abstract
The invention discloses a preparation method and a device of an enhanced diamond field effect transistor, wherein the method comprises the following steps: growing a p-type doped diamond layer on the intrinsic diamond layer; performing hydrogen termination treatment on the device surface of the p-type doped diamond layer to form a hydrogen-terminated conductive layer on the device surface of the p-type doped diamond layer; removing the hydrogen terminal conducting layer in the grid position area, and respectively depositing a source electrode and a drain electrode on the hydrogen terminal conducting layers on two sides of the grid position area; a gate dielectric layer is grown in the region of the gate location on the p-doped diamond layer and a gate electrode is deposited on the gate dielectric layer. The method can prepare the large-current enhanced diamond field effect transistor device.
Description
Technical Field
The invention relates to the technical field of semiconductors, in particular to a preparation method of an enhanced diamond field effect transistor and an enhanced diamond field effect transistor device.
Background
KongThe stone has many excellent properties, such as large forbidden band width (5.5 eV), high breakdown field strength (10 MV/cm), high thermal conductivity (22W/(cm.K)), and high carrier mobility (electrons: 4500 cm) 2 V · s; cavity: 3800cm 2 /(V · s)), and the like, and thus has great application potential in the fields of high-temperature, high-frequency, high-power electronic devices and the like.
At present, when diamond is applied to the field of field effect transistors, a mode of performing hydrogen termination treatment on the surface of the diamond is generally adopted to form a conductive channel in the diamond, and in this mode, the existing hydrogen-terminated diamond field effect transistor is generally a depletion device (a threshold voltage is a negative value, namely a normally open device). However, depletion mode devices increase the complexity of the driver circuit design in applications, reduce its reliability, and cause unnecessary power loss, and thus, enhancement mode diamond field effect transistor devices are required to meet the application requirements.
Disclosure of Invention
Therefore, the technical problem to be solved by the present invention is to solve the problems that the existing depletion type diamond device has high electric energy loss and is difficult to meet the application requirements of the driving circuit, and to provide a preparation method of an enhanced diamond field effect transistor, and an enhanced diamond field effect transistor device prepared by the preparation method.
To this end, according to a first aspect, the present invention provides a method of manufacturing an enhanced diamond field effect transistor, comprising the steps of:
growing a p-type doped diamond layer on the intrinsic diamond layer;
performing hydrogen termination treatment on the device surface of the p-type doped diamond layer to form a hydrogen-terminated conductive layer on the device surface of the p-type doped diamond layer;
removing the hydrogen terminal conducting layer in the grid position area, and respectively depositing a source electrode and a drain electrode on the hydrogen terminal conducting layers on two sides of the grid position area;
a gate dielectric layer is deposited in the region of the gate location on the p-doped diamond layer and a gate electrode is deposited on the gate dielectric layer.
In a possible implementation manner, the step of removing the hydrogen terminal conductive layer in the gate position region and respectively depositing the source electrode and the drain electrode on the hydrogen terminal conductive layers on the two sides of the gate position region specifically includes:
depositing a metal structure layer on the hydrogen terminal conductive layer;
etching to remove the metal structure layer in the grid position area;
removing the hydrogen terminal conducting layer in the grid position area under the oxygen plasma atmosphere;
etching to remove the metal structure layer outside the source position area and the drain position area, and finishing the deposition of the source electrode and the drain electrode; the source position region and the drain position region are respectively positioned at two sides of the grid position region.
In a possible implementation manner, the step of removing the hydrogen termination conductive layer in the gate position region under the oxygen plasma atmosphere specifically includes:
the hydrogen termination conductive layer in the region of the gate location is irradiated using a plasma surface treating machine.
In one possible implementation, the p-type doped diamond layer is a boron doped diamond layer.
In one possible implementation, the metal structure layer is a gold thin film layer.
According to a second aspect, the present invention also provides an enhanced diamond field effect transistor device comprising:
an intrinsic diamond layer;
a p-type doped diamond layer grown on the intrinsic diamond layer; a hydrogen terminal conducting layer is formed on the surface of the device of the p-type doped diamond layer except the grid position region;
the source electrode and the drain electrode are respectively arranged on the hydrogen terminal conducting layers on the two sides of the grid position area;
the grid dielectric layer is arranged in a grid position area on the p-type doped diamond layer;
and the gate electrode is arranged on the gate dielectric layer.
In one possible implementation, the p-type doped diamond layer is a boron doped diamond layer.
The technical scheme provided by the invention has the following advantages:
1. according to the preparation method of the enhancement type diamond field effect transistor, the p-type doped diamond layer with certain conductivity grows on the intrinsic diamond layer, then hydrogen terminal processing is carried out on the region outside the grid position region of the p-type doped diamond layer (the hydrogen terminal processing of the grid position region is carried out together and then is removed), a hydrogen terminal conducting layer with higher conductivity is formed, the p-type doped diamond layer at the moment has the foundation of an enhancement type device, finally, after a grid dielectric layer is deposited through the grid position region on the p-type doped diamond layer, deposition of a grid electrode and a source electrode and a drain electrode is completed, and finally preparation of the enhancement type diamond field effect transistor is achieved.
Meanwhile, on the basis of the p-type doped diamond layer with relatively weak conductivity, the source lower region and the drain lower region in the prepared device are also provided with the hydrogen terminal conducting layer with relatively strong conductivity formed on the surface of the p-type doped diamond layer, so that the current density in the prepared device is high; the prepared under-gate area only has the p-type doped diamond layer with weaker conductivity, so that the gate dielectric layer in the gate position area only requires smaller thickness, and the current loss is reduced; finally, the method can prepare the large-current enhanced diamond field effect transistor device.
2. According to the preparation method of the enhanced diamond field effect transistor, the protective layer used for protecting the hydrogen terminal conducting layer in other areas is arranged to be the metal structure layer when the hydrogen terminal conducting layer in the grid position area is removed, and the metal structure layer is directly etched to form the source electrode and the drain electrode after the hydrogen terminal conducting layer in the grid position area is removed, so that the flow of the preparation method can be simplified, the material loss in the process of executing the method is reduced, and the cost is reduced.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.
Fig. 1 is a flow chart of a method for manufacturing an enhanced diamond field effect transistor according to an embodiment of the present invention;
fig. 2 is a schematic diagram of an enhanced diamond field effect transistor device according to an embodiment of the present invention;
FIG. 3 is a flowchart illustrating the detailed steps of step S30 in FIG. 1;
fig. 4A to 4D are schematic structural diagrams of the device manufactured in step S31 to step S34, respectively;
description of the reference numerals:
1-a layer of intrinsic diamond; a 2-p type doped diamond layer; 2 a-a hydrogen termination conductive layer; 3-a metal structure layer; 3 a-a source electrode; 3 b-a drain electrode; 4-a gate dielectric layer; 5-a gate electrode.
Detailed Description
The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it is to be understood that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
In the description of the present invention, it should be noted that the terms "upper", "lower", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, which are merely for convenience of describing the present invention and simplifying the description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.
Example 1
Fig. 1 shows a method flowchart of a method for manufacturing an enhanced diamond field effect transistor provided in this embodiment, and fig. 2 shows a structure of an enhanced diamond field effect transistor device manufactured by the method. As shown in fig. 1, the method comprises the steps of:
s10: a p-type doped diamond layer 2 is grown on the intrinsic diamond layer 1.
In this embodiment, the intrinsic diamond layer 1 may be prepared together during the whole process, or may be a preform obtained directly.
In this embodiment, the p-type doped diamond layer 2 may be a boron-doped diamond layer, or may be a diamond layer doped with other group iii elements such as indium or gallium. Specifically, taking the p-type doped diamond layer 2 as an example of a boron-doped diamond layer, the boron-doped diamond layer can be grown in a Microwave Plasma Chemical Vapor Deposition (MPCVD) device, and the specific growth conditions can be that the cavity pressure is 140 mbar-170 mbar, the temperature is 700 ℃ -1000 ℃, the methane concentration is 5 sccm-10 sccm, the hydrogen flow is 80 sccm-120 sccm, and the oxygen flow is 0.3 sccm-1.0 sccm. In particular, the thickness of the boron doped diamond layer may be between 500nm and 900 nm.
S20: the device surface of the p-type doped diamond layer 2 was subjected to hydrogen termination treatment to form a hydrogen-terminated conductive layer 2a on the device surface of the p-type doped diamond layer 2.
Similarly, the hydrogen end treatment can also be carried out in an MPCVD device, specifically, the atmosphere in the MPCVD device is hydrogen plasma gas, the pressure of a cavity in the MPCVD device is set to be between 80 and 120mbar, the temperature is set to be between 700 and 1000 ℃, the microwave power is set to be between 1.8 and 2.5kW, and the surface of the device of the p-type doped diamond layer 2 is treated for 5 to 15min. It should be noted that the device surface here refers to the other surface of the p-doped diamond layer 2 opposite to the surface in contact with the intrinsic diamond layer 1, i.e. the upper surface of the p-doped diamond layer 2 in the state shown in figure 2.
It should be noted that, as shown in fig. 2, the hydrogen-terminated conductive layer 2a formed here is not a new structural layer grown on the p-type doped diamond layer 2, but two-dimensional hole gas is formed in the p-type doped diamond layer 2 near the device surface, and the two-dimensional hole gas is confined in a thin layer of several nanometers, that is, the hydrogen-terminated conductive layer 2a.
S30: the hydrogen terminal conductive layer 2a in the gate position area is removed, and a source electrode 3a and a drain electrode 3b are deposited on the hydrogen terminal conductive layer 2a on both sides of the gate position area, respectively.
Specifically, the hydrogen termination conductive layer 2a in the gate position region may be removed by providing a protective layer in a region other than the gate position region, and then treating the hydrogen termination conductive layer 2a in the gate position region under an oxygen atmosphere, specifically, heating the p-type doped diamond layer 2 under an ozone atmosphere, or treating and removing the hydrogen termination conductive layer 2a in the gate position region by means of oxygen plasma irradiation.
S40: a gate dielectric layer 4 is grown in the region of the gate location on the p-doped diamond layer 2 and a gate electrode 5 is deposited on the gate dielectric layer 4.
Specifically, the gate dielectric layer 4 may be Al 2 O 3 Layer or HfO 2 Layers, etc., which may be between 15nm and 25nm thick.
Specifically, the gate dielectric layer 4 may be grown only in the gate position region on the p-type doped diamond layer 2, or may be grown in all regions of the p-type doped diamond layer 2 except for the source electrode 3a and the drain electrode 3b, so as to achieve the effect of a passivation layer, effectively protect the two-dimensional hole gas in the hydrogen terminal conductive layer 2a, and further improve the stability of the device prepared by the method in this embodiment.
In the preparation method of the enhancement type diamond field effect transistor in the embodiment, the p-type doped diamond layer 2 with certain conductivity is grown on the intrinsic diamond layer 1, then hydrogen termination processing is performed on the region outside the gate position region of the p-type doped diamond layer 2 (the hydrogen termination processing of the gate position region is removed after being performed), and the hydrogen termination conductive layer 2a with higher conductivity is formed, so that the p-type doped diamond layer 2 has the foundation of an enhancement type device, and finally, after the gate dielectric layer 4 is grown through the gate position region on the p-type doped diamond layer 2, deposition of the gate electrode 5, the source electrode 3a and the drain electrode 3b is completed, and finally, the preparation of the enhancement type diamond field effect transistor is realized.
Meanwhile, on the basis of the p-type doped diamond layer 2 with relatively weak conductivity, the source lower region and the drain lower region in the prepared device are also provided with the hydrogen terminal conducting layer 2a with relatively strong conductivity formed on the surface of the p-type doped diamond layer 2, so that the current density in the prepared device is high; the prepared under-gate area only has the p-type doped diamond layer 2 with weaker conductivity, so that the gate dielectric layer 4 in the gate position area only requires smaller thickness, and the current loss is reduced; finally, the method can prepare the large-current enhanced diamond field effect transistor device.
In order to further simplify the implementation steps of the method in this embodiment and reduce the cost, in a specific implementation manner of this embodiment, as shown in fig. 3, the step S30 may also specifically include the following steps:
step S31: a metal structure layer 3 is deposited on the hydrogen termination conductive layer 2a.
The device structure prepared by this step is shown in fig. 4A.
Specifically, the metal structure layer 3 may be a thick gold thin film, and may be grown by electron beam evaporation or the like, and the thickness thereof may be between 90nm and 120 nm.
Step S32: and etching to remove the metal structure layer 3 in the area of the grid position.
The device structure prepared by this step is shown in fig. 4B.
Specifically, a photoresist may be first disposed on the metal structure layer 3, the photoresist in the gate position region may be removed by patterning, and finally, the metal structure layer 3 in the gate position region may be removed by etching using a wet etching solution such as a potassium iodide solution, so as to expose the hydrogen termination conductive layer 2a in the gate position region.
Step S33: the hydrogen termination conductive layer 2a in the region of the gate position is removed in an oxygen plasma atmosphere.
The device structure prepared by this step is shown in fig. 4C.
Step S34: and etching to remove the metal structure layer 3 outside the source position area and the drain position area, and finishing the deposition of the source electrode 3a and the drain electrode 3b.
The device structure prepared by this step is shown in fig. 4D.
Specifically, the source location region and the drain location region are located on both sides of the gate location region, respectively.
Specifically, a photoresist may be disposed on the metal structure layer 3 (and the p-type doped diamond layer 2 in the gate position region), the photoresist in the region other than the source position region and the drain position region may be removed by patterning, and finally, a wet etching solution such as a potassium iodide solution may be used to remove the portion not covered by the photoresist by etching, so that only the metal structure layer 3 in the source position region and the drain position region is remained, and the source electrode 3a and the drain electrode 3b are correspondingly formed.
Example 2
This embodiment provides an enhancement mode diamond field effect transistor device, which is prepared by the method for preparing the enhancement mode diamond field effect transistor in embodiment 1, and thus the content already stated in embodiment 1 is not repeated in this embodiment.
As shown in fig. 2, the device includes: intrinsic diamond layer 1, p-type doped diamond layer 2, source electrode 3a, drain electrode 3b, gate dielectric layer 4 and gate electrode 5.
Wherein a p-type doped diamond layer 2 is grown on the intrinsic diamond layer 1 and the device surface of the p-type doped diamond layer 2 is formed with a hydrogen termination conductive layer 2a except for the gate location region. The source electrode 3a and the drain electrode 3b are respectively arranged on the hydrogen terminal conducting layer 2a at two sides of the grid position area, the grid dielectric layer 4 is arranged on the grid position area on the p-type doped diamond layer 2, and the grid electrode 5 is arranged on the grid dielectric layer 4.
In particular, the p-type doped diamond layer 2 may be a boron doped diamond layer.
Specifically, the gate dielectric layer 4 may be further disposed on the gate position region on the p-type doped diamond layer 2, or may be disposed on all regions of the p-type doped diamond layer 2 except for the source electrode 3a and the drain electrode 3b, so as to achieve the effect of a passivation layer at the same time.
The enhancement mode diamond field effect transistor device in the embodiment is low in manufacturing cost and high in current density.
It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications therefrom are intended to be within the scope of the invention.
Claims (7)
1. A preparation method of an enhanced diamond field effect transistor is characterized by comprising the following steps:
growing a p-type doped diamond layer on the intrinsic diamond layer;
performing a hydrogen termination treatment on the device surface of the p-type doped diamond layer to form a hydrogen-terminated conductive layer on the device surface of the p-type doped diamond layer;
removing the hydrogen terminal conducting layer in the grid position area, and respectively depositing a source electrode and a drain electrode on the hydrogen terminal conducting layer at two sides of the grid position area;
and growing a gate dielectric layer in the region of the gate position on the p-type doped diamond layer, and depositing a gate electrode on the gate dielectric layer.
2. The method of manufacturing an enhancement mode diamond field effect transistor according to claim 1, wherein said step of removing said hydrogen termination conductive layer in a gate location area and depositing a source electrode and a drain electrode on said hydrogen termination conductive layer on both sides of said gate location area, respectively, comprises:
depositing a metal structure layer on the hydrogen terminal conductive layer;
etching to remove the metal structure layer in the grid position area;
removing the hydrogen termination conductive layer in the region of the gate location under an oxygen plasma atmosphere;
etching to remove the metal structure layer outside the source position area and the drain position area, and finishing the deposition of the source electrode and the drain electrode; the source position region and the drain position region are respectively located on two sides of the gate position region.
3. The method for manufacturing an enhancement mode diamond field effect transistor according to claim 2, wherein the step of removing the hydrogen termination conductive layer in the gate location area under an oxygen plasma atmosphere specifically comprises:
irradiating the hydrogen termination conductive layer in the gate location region using a plasma surface treating machine.
4. A method of manufacturing an enhanced diamond field effect transistor according to any of claims 1-3, wherein the p-doped diamond layer is a boron doped diamond layer.
5. The method of manufacturing an enhancement mode field effect transistor according to any one of claims 1 to 3, wherein the metal structure layer is a gold thin film layer.
6. An enhanced diamond field effect transistor device, comprising:
an intrinsic diamond layer;
a p-type doped diamond layer grown on the intrinsic diamond layer; a hydrogen terminal conducting layer is formed on the surface of the device of the p-type doped diamond layer except for the grid position region;
the source electrode and the drain electrode are respectively arranged on the hydrogen terminal conducting layers on two sides of the grid position area;
the grid dielectric layer is arranged in the grid position region on the p-type doped diamond layer;
and the gate electrode is arranged on the gate dielectric layer.
7. The enhancement mode field effect transistor device of claim 6 wherein said p-type doped diamond layer is a boron doped diamond layer.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN118398666A (en) * | 2024-06-25 | 2024-07-26 | 深圳市港祥辉电子有限公司 | P-type transverse diamond MOSFET device and preparation method thereof |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN118398666A (en) * | 2024-06-25 | 2024-07-26 | 深圳市港祥辉电子有限公司 | P-type transverse diamond MOSFET device and preparation method thereof |
| CN118398666B (en) * | 2024-06-25 | 2024-09-10 | 深圳市港祥辉电子有限公司 | P-type transverse diamond MOSFET device and preparation method thereof |
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