TWI677099B - Graphene transistor for bone conduction devices - Google Patents

Abstract

A graphene transistor for a bone conduction device includes a substrate, a sub-emitter, an emitter, a spacer layer, a gradient base, a first gradient layer, a collector, a second gradient layer, a surface layer, and a graphite thin layer. The hole wall of the substrate defines a perforation. The secondary emitter is stacked on the upper surface of the substrate and has a sealing section, and the sealing section closes one end of the perforation. The emitter is stacked on the secondary emitter. The interval is stacked on the secondary emitter and is located on one side of the emitter. The gradient base is stacked on the emitter and the spacer. The first gradation is stacked on the gradation base. The collector is stacked on the first gradient layer. The second gradient is stacked on the collector. The surface is stacked on the second gradient layer. The graphite thin layer covers the sealing section and the lower surface of the substrate and the hole wall. The graphene transistor of the bone conduction device has good gain and additional power efficiency.

Description

Graphene transistor for bone conduction device

The invention relates to a graphene transistor, in particular to a graphene transistor for a bone conduction device.

A bone conduction device in the prior art, such as a bone conduction headset, sends a sound wave signal to the skull to cause the skull to vibrate and directly transmit to the inner ear lymph, which in turn transmits to the brain hearing system to produce hearing. The advantage of the bone conduction device is that the sound is not transmitted to the brain's hearing system through the ears, so that users can still receive the sound of the surrounding environment when wearing the bone conduction device, thereby reducing the chance of accidents caused by the inability to hear outside sounds. .

The prior art bone conduction device includes a communication chip, a sensor, and a micromotor. The communication chip is used to send sound waves to the skull to produce hearing. However, the prior art communication chips have poor performance in Gain and Power-Added Efficiency (PAE), which makes the strength of the sound signal insufficient, making it difficult for users to clearly receive the transmission from the bone conduction device. Sound signal, it is difficult to hear the sound content of the bone conduction device.

The invention provides a graphene transistor for a bone conduction device, which can improve gain and additional power efficiency.

The graphene transistor for a bone conduction device provided by the present invention includes a substrate, a secondary emitter, an emitter, a spacer layer, a graded base, a first graded layer, a collector, a second graded layer, a surface layer, and graphite. Floor. The substrate includes an upper surface, a lower surface opposite to the upper surface, and a hole wall connected between the upper surface and the lower surface. The hole wall defines a perforation. The secondary emitter is stacked on the upper surface and has a sealing section, and the sealing section closes one end of the perforation. The emitter is stacked on the secondary emitter. The interval is stacked on the secondary emitter and is located on one side of the emitter. The gradient base is stacked on the emitter and the spacer. The first gradation is stacked on the gradation base. The collector is stacked on the first gradient layer. The second gradient is stacked on the collector. The surface is stacked on the second gradient layer. The graphene layer covers the lower surface, the hole wall and the sealing section.

In an embodiment of the present invention, the above-mentioned substrate, sub-emitter, spacer layer and collector include gallium arsenide, the emitter includes indium gallium phosphide, the gradient base includes indium gallium arsenide, and the gradient base The contained indium and gallium are used as a reference, and the mole fraction of indium contained in the graded base is gradually increased from the spacer layer toward the first graded layer.

In an embodiment of the present invention, the first gradient layer includes indium gallium arsenide, and based on the indium and gallium contained in the first gradient layer, the molar fraction of indium contained in the first gradient layer It gradually decreases from the gradient base to the collector.

In an embodiment of the present invention, the highest mole fraction of indium contained in the first gradient layer is not more than the highest mole fraction of indium contained in the gradient base; Indium and gallium are used as the basis. The highest Molar fraction of indium contained in the gradient base is 0.05 to 0.15.

In an embodiment of the present invention, the second gradient layer includes indium gallium arsenide, and based on the indium and gallium contained in the second gradient layer, the molar fraction of indium contained in the second gradient layer Increasing from collector to surface layer.

In an embodiment of the present invention, in the graphene transistor for a bone conduction device described above, based on the indium and phosphorus contained in the emitter, the molar fraction of indium contained in the emitter is 0.45. To 0.55.

In one embodiment of the present invention, the surface layer includes indium gallium arsenide.

In an embodiment of the present invention, the highest mole fraction of indium contained in the second gradient layer is not more than the mole fraction of indium contained in the surface layer; the indium contained in the surface layer and Based on gallium, the molar fraction of indium contained in the surface layer is 0.45 to 0.55.

In an embodiment of the present invention, the above-mentioned graphene transistor for a bone conduction device further includes a corrosion-resistant layer, the corrosion-resistant layer is disposed between the secondary emitter and the upper surface, and the graphene layer passes through the corrosion-resistant layer Cover the sealing section.

In an embodiment of the present invention, the above-mentioned corrosion-resistant layer includes indium gallium phosphide. Based on the indium and gallium contained in the corrosion-resistant layer, the molar fraction of indium contained in the corrosion-resistant layer is 0.45 to 0.55.

The graphene transistor for the bone conduction device of the present invention has good gain and additional power efficiency, which is beneficial to improving the sound signal transmission intensity of the bone conduction device, so that the user can more clearly receive the signal from the bone conduction device. The sound signal sent.

FIG. 1 is a schematic diagram of a graphene transistor for a bone conduction device according to an embodiment of the present invention. Please refer to FIG. 1. The graphene transistor 100 for a bone conduction device in this embodiment includes a substrate 110, a secondary emitter 120, an emitter 125, a spacer layer 130, a gradient base 140, a first gradient layer 150, and a collector. 160, a second gradation layer 170, a surface layer 180, and a graphite thin layer 190. The substrate 110 includes an upper surface 111, a lower surface 112, and a hole wall 113. The lower surface 112 is opposite to the upper surface 111. The hole wall 113 connects the upper surface 111 and the lower surface 112. The hole wall 113 defines a perforation. 111 and the lower surface 112 are connected. The sub-emitter 120 is stacked on the upper surface 111 and has a sealing section 121. The sealing section 121 closes one end of the perforation connected to the upper surface 111. The emitter 125 is stacked on the secondary emitter 120. The spacer layer 130 is stacked on the secondary emitter 120 and is located on one side of the emitter 125. The graded base 140 is stacked on the spacer layer 130 and the emitter 125. The first gradient layer 150 is stacked on the gradient base 140. The collector 160 is stacked on the first gradient layer 150. The second gradient layer 170 is stacked on the collector 160. The surface layer 180 is stacked on the second gradient layer 170. The graphite thin layer 190 covers the lower surface 112, the hole wall 113 and the sealing section 121. The graphene layer 190 is made of graphene. A through hole 191 may be formed in the graphene layer 190 to expose a part of the lower surface 112, but the invention is not limited thereto. The graphene layer 190 can improve heat dissipation and avoid the problem of transistor performance degradation caused by heat accumulation.

In this embodiment, the substrate 110, the sub-emitter 120, the spacer 130, and the collector 160 may be made of gallium arsenide (GaAs), the emitter 125 may be made of indium gallium phosphide (InGaP), and a graded base 140. The first gradient layer 150, the second gradient layer 170, and the surface layer 180 may be made of indium gallium arsenide (InGaAs), but the present invention is not limited thereto. In addition, in this embodiment, based on the indium and gallium contained in the gradient base 140, the mole fraction of indium contained in the gradient base 140 gradually increases from the spacer layer 130 toward the first gradient layer 150; Based on the indium and gallium contained in the first gradient layer 150, the molar fraction of indium contained in the first gradient layer 150 gradually decreases from the gradient base 140 to the collector 160, and the second gradient layer 170 Based on the contained indium and gallium, the mole fraction of indium contained in the second graded layer 170 gradually increases from the collector 160 to the surface layer 180.

Further, at the boundary between the gradient base 140 and the spacer layer 130, the Mohr fraction of the indium contained in the gradient base 140 may approach the Mohr fraction of the indium contained in the spacer layer 130. At the boundary between the gradient base 140 and the first gradient layer 150, the Mohr fraction of indium contained in the gradient base 140 may approach or be equal to the Mohr fraction of indium contained in the first gradient layer 150, and That is, the molar fraction of indium contained in the first graded layer 150 does not exceed the molar fraction of indium contained in the graded base 140. In this embodiment, since the spacer layer 130 is made of gallium arsenide and does not contain indium, the Mohr fraction of indium contained in the graduated base 140 tends to be at the boundary between the graduated base 140 and the spacer 130. Nearly 0. At the same time, at the interface between the gradient base 140 and the first gradient layer 150, the molar fraction of indium contained in the gradient base 140 may be 0.1, and the molar fraction of indium contained in the first gradient layer 150 may be It is 0.1 or less. Furthermore, for the first gradient layer 150 and the gradient base 140 as a whole, the highest mole fraction of indium contained in the first gradient layer 150 does not exceed the highest mole ratio of indium contained in the gradient base 140. Ear fraction; taking this embodiment as an example, at the junction of the gradient base 140 and the first gradient layer 150, the mole fraction of indium contained in the gradient base 140 has the highest value, and The mole fraction of indium contained has the highest value; that is, the highest mole fraction of indium contained in the graded base 140 may be 0.1, and the highest mole fraction of indium contained in the first graded layer 150 The fraction does not exceed 0.1.

In addition, at the boundary between the first gradient layer 150 and the collector 160, the Mohr fraction of the indium contained in the first gradient layer 150 may approach the Mohr fraction of the indium contained in the collector 160; similarly At the boundary between the second gradient layer 170 and the collector 160, the Mohr fraction of the indium contained in the second gradient layer 170 may approach the Mohr fraction of the indium contained in the collector 160. In this embodiment, since the collector 160 is made of gallium arsenide and does not contain indium, at the boundary between the first gradient layer 150 and the collector 160, the mole of indium contained in the first gradient layer 150 is The fraction ratio approaches 0, and at the boundary between the second gradient layer 170 and the collector 160, the Mohr fraction of indium contained in the second gradient layer 170 approaches 0.

In addition, at the boundary between the second gradient layer 170 and the surface layer 180, the Mohr fraction of indium contained in the second gradient layer 170 may approach or be equal to the Mohr fraction of indium contained in the surface layer 180. That is, the molar fraction of indium contained in the second graded layer 170 does not exceed the molar fraction of indium contained in the surface layer 180. In this embodiment, based on the indium and gallium contained in the surface layer 180, the Mohr fraction of the indium contained in the surface layer 180 may be, for example, 0.5, and accordingly, the second gradient layer 170 and the surface layer At the junction of 180, the Mohr fraction of indium contained in the second gradient layer 170 may be 0.5 or less. Furthermore, for the second gradient layer 170 as a whole, the highest molar fraction of indium contained in the second gradient layer 170 does not exceed the molar fraction of indium contained in the surface layer 180; As an example, at the interface between the second gradient layer 170 and the surface layer 180, the Mohr fraction of the indium contained in the second gradient layer 170 has the highest value; as described above, the indium contained in the surface layer 180 has the highest value. The Mohr fraction may be, for example, 0.5, so the highest Mohr fraction of indium contained in the second gradient layer 170 does not exceed 0.5.

The above-mentioned graphene transistor 100 for a bone conduction device may further include an etching resist layer 195, which is disposed between the sub-emitter 120 and the upper surface 111, and the graphene layer 190 is covered by the etching resist layer 195. Sealing section 121. Accordingly, when the through hole is formed by etching, the secondary emitter 120 can be protected from damage. In this embodiment, the substrate 110 and the secondary emitter 120 are made of gallium arsenide. The substrate 110 may be etched using hydrochloric acid to form a through hole, and indium gallium phosphide is used as the resist layer 195 to protect the secondary emitter 120. For example, based on the indium and gallium contained in the resist layer 195, the Mohr fraction of the indium contained in the resist layer 195 is 0.5.

In this embodiment, the gallium arsenide / indium gallium phosphide (GaAs / InGaP) material system used in the graphene transistor 100 for a bone conduction device applies disordered matching to the gallium arsenide lattice. Indium gallium phosphide; that is, in this embodiment, the indium gallium phosphide of the emitter 125 is disordered. And in this embodiment, based on the indium and gallium contained in the emitter 125 as a reference, the Mohr fraction of the indium contained in the emitter 125 is 0.5.

The doping concentration of the above-mentioned sub-emitter 120 may be, for example, 3 × 10 ¹⁸ cm ^-3 to 5 × 10 ¹⁸ cm ^-3 , and the doping concentration of the emitter 125 may be, for example, 4 × 10 ¹⁷ cm ^-3 to 5 × 10 doping concentration of ¹⁷ cm ^-3, the gradient of the base 140 may be, for example, 5 × 10 ¹⁸ cm ^-3 to 3 × 10 ¹⁹ cm ^-3, the doping concentration of the first graded layer 150 may be, for example, 1 × 10 ¹⁶ cm ^{- 3} to 4 × 10 ¹⁶ cm ^-3 , for example, the doping concentration of the collector 160 may be 2 × 10 ¹⁶ cm ^-3 to 4 × 10 ¹⁶ cm ^-3 , and the doping concentration of the second gradient layer 170 may be 1 × 10 ¹⁹ cm ^-3 to 2 × 10 ¹⁹ cm ^-3 , the doping concentration of the surface layer 180 may be, for example, 1 × 10 ¹⁹ cm ^-3 to 2 × 10 ¹⁹ cm ^-3 , and the doping concentration of the resist layer 195 is, for example, It can be from 2 × 10 ¹⁸ cm ^-3 to 4 × 10 ¹⁸ cm ^-3 . In this embodiment, the doping concentration of the secondary emitter 120 is 5 × 10 ¹⁸ cm ^-3 , the doping concentration of the emitter 125 is 5 × 10 ¹⁷ cm ^-3 , and the doping concentration of the graded base 140 is 3 × 10 ¹⁹ cm ^-3 , the doping concentration of the first gradient layer 150 is 4 × 10 ¹⁶ cm ^-3 , the doping concentration of the collector 160 is 3 × 10 ¹⁶ cm ^-3 , and the doping concentration of the second gradient layer 170 is 1 × 10 ⁹ cm ^-3 , the doping concentration of the surface layer 180 is 1 × 10 ¹⁹ cm ^-3 , and the doping concentration of the resist layer 195 is 4 × 10 ¹⁸ cm ^-3 , and the doping concentration of the spacer layer 130 is It is 0 cm ^-3 , that is, the spacer layer 130 is made of an intrinsic semiconductor material, but the present invention is not limited thereto. In addition, in this embodiment, the graphene transistor 100 used for the bone conduction device is an NPN type transistor, that is, the emitter 125 is an N type, the gradient base 140 is a P type, and the collector 160 is an N type. ; But in other embodiments, the graphene transistor 100 for a bone conduction device may also be a PNP type transistor, that is, the emitter 125 is a P type, the gradient base 140 is an N type, and the collector 160 is P type.

In addition, the thickness of the secondary emitter 120 may be, for example, 550 nanometers (nm) to 1000 nm, the thickness of the emitter 125 may be, for example, 25 nm to 35 nm, and the thickness of the spacer layer 130 may be, for example, 3 nm to 7 nm. The thickness of the base 140 may be, for example, 65 nm to 75 nm. The thickness of the first gradient layer 150 may be, for example, 15 nm to 25 nm. The thickness of the collector 160 may be, for example, 550 nm to 650 nm. The thickness may be, for example, 45 nm to 55 nm, the thickness of the surface layer 180 may be, for example, 45 nm to 55 nm, and the thickness of the substrate 110 may be, for example, 50 μm to 100 μm. In this embodiment, the thickness of the secondary emitter 120 is 6000 nm, the thickness of the emitter 125 is 30 nm, the thickness of the spacer layer 130 is 5 nm, the thickness of the gradient base 140 is 60 nm, and the thickness of the first gradient layer 150 The thickness is 20 nm, the thickness of the collector 160 is 600 nm, the thickness of the second gradient layer 170 is 50 nm, the thickness of the surface layer 180 is 50 nm, and the thickness of the substrate 110 is 50 μm, but the present invention is not limited thereto.

The graphene transistor 100 for a bone conduction device of this embodiment can be applied to a communication chip of a bone conduction device to send a signal. In order to illustrate the advantages that the graphene transistor 100 for a bone conduction device of this embodiment can achieve, the graphene transistor 100 for a bone conduction device of this embodiment and a commercial electricity for a bone conduction device are further described below. The crystal (comparative example) was tested for gain (Gain) and power-added efficiency (PAE). In terms of structure, the graphene transistor 100 for the bone conduction device different from this embodiment belongs to the bipolar junction transistor (BJT). The commercially available transistor for the bone conduction device is Field-Effect Transistor (FET).

FIG. 2 is a graph comparing the gain of a graphene transistor for a bone conduction device with a commercially available transistor for a bone conduction device according to an embodiment of the present invention. Please refer to FIG. 2. At the same input power, the gain of the graphene transistor 100 for a bone conduction device in this embodiment is greater than the gain of a commercially available transistor for a bone conduction device. For example, when the input power (Pin) is 15 dBm, the gain of the graphene transistor 100 for a bone conduction device in this embodiment can reach about 11 dB. The gain of a transistor for a bone conduction device is commercially available. Only about 9 dB.

FIG. 3 is a comparison diagram of additional power efficiency of a graphene transistor for a bone conduction device and a commercially available transistor for a bone conduction device according to an embodiment of the present invention. Referring to FIG. 3, at the same input power, the additional power efficiency of the graphene transistor 100 for a bone conduction device of this embodiment is greater than the additional power efficiency of a commercially available transistor for a bone conduction device. For example, when the input power (Pin) is 15 dBm, the additional power efficiency of the graphene transistor 100 for a bone conduction device of this embodiment can reach about 31%. A commercially available transistor for a bone conduction device The additional power efficiency is only about 28.5%.

It can be seen from the above test that the graphene transistor 100 for a bone conduction device in this embodiment can achieve better gain and additional power efficiency than a commercially available transistor for a bone conduction device. According to this, when the graphene transistor 100 for the bone conduction device of this embodiment is applied to the communication chip of the bone conduction device, the sound signal transmission strength of the bone conduction device can be further improved, so that the user can receive more clearly. To the sound signal from the bone conduction device.

In summary, the graphene transistor for a bone conduction device according to the embodiment of the present invention has good gain and additional power efficiency, which is helpful to improve the sound signal transmission strength of the bone conduction device, so that the user can more clearly Received a sound signal from a bone conduction device.

100‧‧‧graphene transistor

110‧‧‧ substrate

111‧‧‧ top surface

112‧‧‧ lower surface

113‧‧‧hole wall

120‧‧‧emitters

121‧‧‧Sealed Section

125‧‧‧ Emitter

130‧‧‧ spacer

140‧‧‧ gradient base

150‧‧‧ the first gradient layer

160‧‧‧collector

170‧‧‧Second Gradient Layer

180‧‧‧ surface layer

190‧‧‧graphene layer

191‧‧‧through hole

195‧‧‧Etching layer

1 is a schematic diagram of a graphene transistor for a bone conduction device according to an embodiment of the present invention;
FIG. 2 is a graph comparing the gain of a graphene transistor for a bone conduction device with a commercially available transistor for a bone conduction device according to an embodiment of the present invention; and FIG. 3 is a diagram for a bone conduction device according to an embodiment of the present invention A graph comparing the additional power efficiency of a graphene transistor with a commercially available transistor for bone conduction devices.

Claims (10)

A graphene transistor for a bone conduction device includes:
A substrate including an upper surface, a lower surface opposite to the upper surface, and a hole wall connected between the upper surface and the lower surface, the hole wall defining a perforation;
A single emitter, which is stacked on the upper surface and has a mouth section which closes one end of the perforation;
One emitter is stacked on the secondary emitter;
A spacer layer stacked on the secondary emitter and located on one side of the emitter;
A graded base electrode stacked on the emitter electrode and the spacer layer;
A first gradient layer stacked on the gradient base;
A set of poles stacked on the first gradient layer;
A second gradient layer superposed on the collector;
A surface layer is stacked on the second gradient layer; and a graphite thin layer is covered on the lower surface, the hole wall and the sealing section. The graphene transistor for a bone conduction device according to claim 1, wherein the substrate, the secondary emitter, the spacer layer, and the collector include gallium arsenide, the emitter includes indium gallium phosphide, and the gradient The base includes indium gallium arsenide, and based on the indium and gallium contained in the graded base, the mole fraction of indium contained in the graded base gradually increases from the spacer layer toward the first graded layer. The graphene transistor for a bone conduction device according to claim 2, wherein the first gradient layer includes indium gallium arsenide, and based on the indium and gallium contained in the first gradient layer, the first gradient layer The mole fraction of indium contained in the layer decreases from the graded base toward the collector. The graphene transistor for a bone conduction device according to claim 3, wherein:
Based on the indium and gallium contained in the graded base, the highest mole fraction of indium contained in the graded base is 0.05 to 0.15; and the highest mole fraction of indium contained in the first graded layer. The ratio does not exceed the highest mole fraction of indium contained in the graded base. The graphene transistor for a bone conduction device according to claim 2, wherein the second gradient layer includes indium gallium arsenide, and based on the indium and gallium contained in the second gradient layer, the second gradient layer The mole fraction of indium contained in the layer gradually increases from the collector toward the surface layer. The graphene transistor for a bone conduction device according to claim 2, wherein the molar fraction of indium contained in the emitter is 0.45 to 0.55 based on indium and phosphorus contained in the emitter. . The graphene transistor for a bone conduction device according to claim 2, wherein the surface layer includes indium gallium arsenide. The graphene transistor for a bone conduction device according to claim 5, wherein:
The surface layer includes indium gallium arsenide, and based on the indium and gallium contained in the surface layer, the molar fraction of indium contained in the surface layer is 0.45 to 0.55; and the second gradient layer contains The highest mole fraction of indium does not exceed the mole fraction of indium contained in the surface layer. The graphene transistor for a bone conduction device according to claim 1, further comprising an etching resist layer disposed between the secondary emitter and the upper surface, and the graphene layer is passed through the The corrosion-resistant layer covers the sealing section. The graphene transistor for a bone conduction device according to claim 9, wherein the corrosion resistance layer includes indium gallium phosphide, and based on the indium and gallium contained in the corrosion resistance layer, the corrosion resistance layer contains The molar fraction of indium contained is 0.45 to 0.55.