JP3076954B2 - Diamond bridge or diamond cantilever, method of manufacturing the same, and electronic device using the diamond bridge or diamond cantilever - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a diamond bridge or a diamond cantilever applied to an electronic device requiring environmental resistance, a sensor such as a strain sensor, and other measuring or controlling electronic devices, and a method of manufacturing the same.
And an electronic device using the diamond bridge or the diamond cantilever.

[0002]

2. Description of the Related Art Conventionally, as a unit used for a vibrating rod transducer, a diamond layer forming a main surface on each of opposite sides, a support bonded to one main surface of each diamond layer, Bridging strips for bridging diamonds are known which have at least one unsupported bridging strip connecting the supported diamond layers and integrally formed therewith. JP-A-5-149760). This unit forms a bridging strip by processing a support serving as a substrate.

[0003]

The conventional unit is
There is an inconvenience that the application to the industrial field is restricted when processing a fine support to be a substrate. That is, a great deal of time and labor is required for processing the fine substrate, and it is extremely difficult to obtain dimensional accuracy and strength of the substrate, which is unsuitable for mass production and expensive. In addition, there is no description of a diamond cantilever in the above.

An object of the present invention is to provide a diamond bridge or a diamond cantilever which has good environmental resistance, has sufficient dimensional accuracy and strength and can be manufactured relatively easily, and a method for manufacturing the same, and uses the diamond bridge or the diamond cantilever. It is an object to provide an electronic device that can be mass-produced.

[0005]

According to the present invention, a diamond bridge or a diamond cantilever is provided.
Silicon, SiC, Si ₃ N ₄ , Ta, Mo or WC
A diamond film formed on the diamond foundation film provided on the substrate, the diamond film is the diamond
Over the temporary sacrificial layer from the base film surface.
After the film is formed, the cavity formed by removing the sacrificial layer is
By adopting a configuration with the diamond base film
Thus, the above-mentioned object is achieved. In addition , the diamond bridge or diamond cantilever is provided with an oxide film on a silicon, SiC or Si ₃ N ₄ substrate, and after the oxide film is damaged, a part of the oxide film is removed to expose the substrate surface. A resist is provided on the exposed surface and on the surface of the oxide film to be a sacrificial layer, which is a part of the oxide film continuous with the exposed surface, and then ion-implanted into the oxide film surface using the resist as a mask. To form a diamond film on the removed surface, remove the sacrificial layer of the oxide film and the remaining oxide film to form a cavity between the diamond film and the substrate, or , Si ₃ N _4, Ta, diamond foundation film is formed on a substrate of Mo or WC, with an oxide film on the diamond foundation film, the oxide film after scratching treatment of the oxide film Removing a portion to expose the surface of the base film, providing a resist on the exposed surface and the surface of the oxide film that is to be a part of the oxide film and is to be a sacrificial layer, Is ion-implanted into the oxide film surface with the mask as a mask, the resist is removed, a diamond film is formed on the removed surface, the sacrificial layer of the oxide film and the remaining oxide film are removed, and the diamond film and the diamond base film are removed. By forming a cavity between them, it can be manufactured relatively easily. Furthermore, a boron-doped diamond film is formed in an island shape on the diamond film of the diamond bridge or diamond cantilever of the present invention, and a titanium layer and a platinum layer are sequentially formed on the boron-doped diamond film to provide a laminated electrode. Thereby, the electronic device can be mass-produced relatively easily.

[0006]

In the diamond bridge or diamond cantilever of the present invention, the space for forming the diamond film in a bridge or cantilever shape is formed by removing a sacrificial layer thereunder. It can be manufactured without cutting, etching, etc., and has good environmental resistance, high dimensional accuracy, and can be easily manufactured without impairing the strength of the substrate. Further, the manufacturing method of the present invention is to provide an oxide film directly on a substrate such as silicon or on a diamond base film, and to damage the oxide film, remove a part of the oxide film after the treatment, and expose the substrate surface. A resist is continuously provided on the exposed surface and on the surface of the oxide film to be a sacrificial layer of a part of the oxide film, and ions are implanted into the oxide film surface using the resist as a mask, and the resist is removed. This is a simple process of forming a diamond film on the removed surface, removing a sacrificial layer of the oxide film and the remaining oxide film to form a cavity between the diamond film and the substrate. And a diamond bridge or a diamond cantilever with high precision and high strength can be manufactured. Further, a boron-doped diamond film is formed in an island shape on the diamond film of the diamond bridge or diamond cantilever of the present invention, and a titanium layer and a platinum layer are sequentially formed on each boron-doped diamond film to provide a laminated electrode. Thus, an electronic device having good environmental resistance can be easily obtained.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described with reference to the attached drawings. 1 and 2 are manufactured by the manufacturing method of the present invention .
In these figures, reference numeral 1 denotes a substrate of silicon, SiC or Si ₃ N ₄ ,
A bridge-like diamond film 3 having a cavity 2 formed by removing a sacrificial layer described later is provided between the substrate 1 and the substrate 1. The thickness of the diamond film 3 in the bridge portion is 3.5 μm, and the height of the cavity 2 is 2 μm. When a load of 1 mg to 40 mg was applied to the center of the bridge portion, deflection proportional to the load was detected. The Young's modulus calculated from the load, the amount of deflection, and the size of the bridge portion was 1242 GPa.

The diamond bridge can be manufactured relatively easily by the manufacturing method shown in FIGS. 3 to 7. More specifically, first, as shown in FIG. 3, a 2 μm thick silicon oxide film is formed on the substrate 1 by sputtering. An oxide film 4 is formed, and the surface of the oxide film 4 is subjected to a damage treatment. Prior to the formation of the oxide film 4, the surface of the substrate 1 is damaged. Subsequently, a resist 5 is developed into a predetermined pattern on the surface of the oxide film 4 by, for example, electron beam lithography as shown in FIG. 4, and using the resist 5 as a mask, the oxide film 4 is etched with buffered hydrofluoric acid to form a substrate 1 Is made (FIG. 5). Although the oxide film 4 is divided into three portions in the cross-sectional view shown in FIG.
A diamond film 3 is formed thereon. in this way,
The portion of the oxide film on which the diamond film 3 is formed is replaced with a sacrificial layer 4.
The sacrificial layer 4a is provided continuously with the hole 6 when viewed from above.

Next, patterning is performed by electron beam lithography so that the resist 5 exists only in the sacrificial layer 4a and the hole 6 in FIG. 5 (FIG. 6).
KeV argon ions were implanted at 1 × 10 ¹⁶ / cm ² . Thereafter, the resist was dissolved and removed using a mixed solution of sulfuric acid and hydrogen peroxide solution. By this ion implantation, the sacrificial layer 4a
The diamond film does not grow except for the hole 6. The size of the sacrificial layer 4a is 460 μm × 240 μm.

Next, as shown in FIG.
To form As described above, diamond grows only in the sacrifice layer 4a and the hole 6 that are not subjected to ion implantation by the resist, and the diamond film 3 is continuously formed on the sacrifice layer from the substrate surface.
Is formed. Thereafter, when the sacrificial layer 4a and the oxide film 4 are etched with buffered hydrofluoric acid, the cavity 2 is formed under the diamond film 3 by removing the sacrificial layer 4a.
And the diamond bridge shown in FIG.

The diamond film is formed by an electron impact CVD (EACVD) method using an apparatus having the structure shown in FIG.
Method). Specifically, the vacuum vessel 10 of the device
The substrate 1 after the step of FIG. 6 is set in the vacuum vessel 1
Introduced hydrogen-diluted methane having a methane concentration of 1% from the gas inlet port 11 to a pressure of 30 Torr.
Was heated to about 2000 ° C. to heat the substrate to about 800 ° C. Then, the substrate 1 was set to a positive voltage, and a DC voltage was applied so that a current of 1.5 A flowed between the filament 12 and the substrate. By this method, a diamond film was formed at a growth rate of about 1 μm / h. Reference numeral 13 denotes a DC power supply, and 14 denotes an AC power supply.

When a diamond cantilever is manufactured, the hole 6 shown in FIG. 5 is made into one place, and a resist is patterned and ion-implanted as shown in FIG. Thus, when the resist is removed and the diamond film 3 is formed by the above method, the diamond film 3 grows into an approximately L-shaped cross section as shown in FIG. 9, and when the oxide film 4 and the sacrificial layer 4a are removed, the diamond cantilever of FIG. Can be

When the substrate 1 is a metal substrate of Ta, Mo or WC, it is necessary to protect the substrate 1 from being etched when the oxide film 4 is etched, and the substrate 1 is made of silicon, SiC, Si ₃ N _{Even with 4} , there is a demand for electrical insulation, improvement in environmental resistance and keeping the temperature of the entire substrate uniform, but in order to satisfy this, it is desirable that a diamond film is provided on the substrate 1. . FIG.
FIGS. 12 and 18 show an embodiment of the present invention in which a diamond bridge or a diamond cantilever is provided on the substrate 1 on which the diamond base film 7 is provided. Layer 4
It has a cavity 2 by removing a, and its manufacturing method is substantially the same as the case where a diamond bridge or a diamond cantilever is directly formed on the substrate 1 described above. That is, an oxide film 4 of a silicon oxide film having a thickness of 2 μm is formed on the diamond base film 7 provided on the substrate 1 by a sputtering method (FIG. 13), and the surface of the oxide film 4 is subjected to a scratching treatment. A resist 5 is developed on the surface of the film 4 into a predetermined pattern (FIG. 14), and the oxide film 4 is developed with buffered hydrofluoric acid.
Is etched to form a hole 6 reaching the diamond base film 7 (FIG. 15), and the resist 5 is formed only in the sacrificial layer 4a and the hole 6.
(FIG. 16), argon ions are implanted using the resist as a mask, and after dissolving and removing the resist, a diamond film 3 is formed on the sacrificial layer 4a and continuous with the diamond base film 7 in each hole 6 (FIG. 16). 17) When the sacrificial layer 4a and the oxide film 4 are removed by etching, a diamond bridge shown in FIG. 12 is obtained. When a diamond cantilever is manufactured, only one hole 6 may be provided.

As shown in FIG. 19, the diamond bridge or the diamond cantilever of the present invention forms a boron-doped diamond film 8 on the diamond film 3 in an island shape, and forms a titanium layer 9 and a platinum layer on the doped diamond film. An electronic device is obtained by laminating 15 and providing a laminated electrode, and can be used as a detection element such as a strain sensor. The diamond bridge or diamond cantilever is resistant to corrosion, can be manufactured precisely on the order of microns, and has sufficient strength, so that an electronic device with good environmental resistance, high accuracy and high strength can be obtained.

[0015]

As described above, according to the first and second aspects of the present invention.
For example, silicon, SiC or Si_ThreeN _FourOn the board,
Is silicon, SiC, Si_ThreeN_Four, Ta, Mo or W
C formed on the diamond base film provided on the C substrate
The diamond film is temporarily removed from the substrate surface or the base film surface.
Is formed over the sacrificial layer provided in
The cavity formed by removing the layer is placed on the substrate or the base film surface.
Excellent environmental resistance and good dimensional accuracy
And high strength diamond bridge or diamond
Claims 4 and 5 are effective in obtaining a cantilever.
According to the invention, silicon, SiC or Si_ThreeN_Fourof
On substrate or silicon, SiC, Si_ThreeN_Four, Ta, M
o on diamond base film formed on o or WC substrate
Then, an oxide film is formed thereon, and after the scratching process, one of the oxide films is formed.
Part to remove the surface of the substrate or the base film,
A portion of the oxide film on the exposed surface of the
A resist was provided on the surface of the oxide film to be a sacrificial layer.
That is, the resist is removed by ion implantation, and
Forming a diamond film, a sacrificial layer of the oxide film and the remaining
The oxide film is removed and the diamond film and the substrate or the base are removed.
The diamond bridges form cavities between the membranes
Or high precision and relatively easy to diamond cantilever
Has the effect of being able to mass-produce
Or diamond cantilever diamond film
A boron-doped diamond film is formed in an island shape on the
A titanium layer and a platinum layer are sequentially formed on a diamond
By providing a laminated electrode, it has excellent environmental resistance,
It is effective in obtaining high-precision, high-strength electronic devices.
You.

[Brief description of the drawings]

[1] oblique view of diamond <br/> command bridge manufactured by the manufacturing method of the present invention

FIG. 2 is a sectional view of FIG.

FIG. 3 is a sectional view of an oxide film forming step according to the invention of claim 3 ;

FIG. 4 is a sectional view of a resist pattern forming step according to the invention of claim 3 ;

FIG. 5 is a sectional view of an etching step according to the invention of claim 3 ;

FIG. 6 is a cross-sectional view of a resist pattern forming step according to the invention of claim 3 ;

FIG. 7 is a cross-sectional view of a diamond film forming step according to the invention of claim 3 ;

FIG. 8 is a sectional view of an oxide film forming step according to another embodiment of the invention of claim 3 ;

Figure 9 is a cross-sectional view of the resist pattern forming step of another embodiment of the invention of claim 3

FIG. 10 shows a diamond produced by the method of the present invention .
Cross section of cantilever

Figure 11 is a perspective view of an embodiment of a diamond bridge of the invention of claim 1

FIG. 12 is a sectional view of FIG. 11;

FIG. 13 is a sectional view of an oxide film forming step according to the invention of claim 4 ;

FIG. 14 is a sectional view of a resist pattern forming step according to the invention of claim 4 ;

FIG. 15 is a sectional view of the etching step according to the invention of claim 4 ;

FIG. 16 is a sectional view of a resist pattern forming step according to the invention of claim 4 ;

FIG. 17 is a sectional view of a diamond film forming step according to the invention of claim 4 ;

FIG. 18 is a sectional view of another embodiment of the invention of claim 1 ;

Figure 19 is a cross-sectional view of an embodiment of a manufacturing process of the invention of claim 5

Figure 20 is a cross-sectional view of an embodiment of a manufacturing process of the invention of claim 5

FIG. 21 is an explanatory view of a diamond film forming step.

[Explanation of symbols]

Reference Signs List 1 substrate 2 cavity 3 diamond film 4 oxide film 4a sacrificial layer 5 resist 6 hole 7 diamond base film 8 boron-doped diamond film 9 titanium layer 15 platinum layer

Continuation of the front page (56) References JP-A-6-267926 (JP, A) JP-A-4-60410 (JP, A) JP-A-5-280970 (JP, A) JP-A-6-216111 (JP) JP-A-61-252656 (JP, A) JP-A-5-149760 (JP, A) Kazuo Sato, Nikkei Electronics, Nikkei BP, August 21, 1989, no. 480, p. 146-149 (58) Fields investigated (Int.Cl. ⁷ , DB name) H01L 21/306 G01B 21/30 G01N 37/00

Claims (5)

(57) [Claims] 1. The method according to claim 1, wherein the silicon, SiC, Si ₃ N ₄ , Ta,
A diamond film formed on a diamond base film provided on a Mo or WC substrate, wherein the diamond film is formed over a temporary sacrificial layer provided from the diamond base film surface. A diamond bridge or a diamond cantilever having a cavity formed by removing the sacrificial layer between the diamond base film and the diamond base film. 2. The diamond bridge or diamond cantilever according to claim 1, wherein the sacrificial layer is a silicon oxide film. 3. An oxide film is formed on a silicon, SiC or Si ₃ N ₄ substrate, and after the oxide film is damaged, a part of the oxide film is removed to expose the substrate surface. After a resist is provided on the surface of the oxide film that is to be a sacrificial layer and is a part of the oxide film that is continuous, ions are implanted into the oxide film surface using the resist as a mask, and the resist is removed to remove the resist. A method of manufacturing a diamond bridge or a diamond cantilever, comprising forming a diamond film on a removal surface, removing a sacrificial layer of the oxide film and the remaining oxide film to form a cavity between the diamond film and the substrate. . 4. Silicon, SiC, Si ₃ N ₄ , Ta,
A diamond base film is formed on a Mo or WC substrate, an oxide film is formed on the diamond base film, and after the oxide film is damaged, a part of the oxide film is removed to expose the surface of the base film. A resist is provided on the surface of the oxide film which is to be a sacrificial layer, which is a part of the oxide film continuous with the exposed surface, and then ion-implanted into the oxide film surface using the resist as a mask; Removing the resist, forming a diamond film on the removed surface, removing the sacrificial layer of the oxide film and the remaining oxide film to form a cavity between the diamond film and the diamond base film. Manufacturing method of diamond bridge or diamond cantilever. 5. A diamond bridges or diamond cantilevers as claimed in any one of claims 1 or claim 2, an island shape to form a boron-doped diamond film on the diamond film, a titanium layer on the boron-doped diamond film And a platinum layer are sequentially formed to provide a laminated electrode.