 Superconducting thin film |
| What is claimed is: 1. A superconducting thin film of a compound oxide represented by YBa.sub.2 Cu.... |
|
| Process of fabricating a semiconductor substrate |
| An object of the present invention is to provide a substrate of good film thickness distribution ... |
|
| Thin film solar cell and production method therefor |
| An object of the present invention is to provide an inexpensive thin film solar cell with high ... |
|
| Soluble precursor to poly (cyanoterephthalydene) and method of preparation |
| The above described problems and others are substantially solved and the above purposes and others ... |
|
| Complementary junction heterostructure field-effect transistor |
| It is a primary object of the present invention to obviate the problems of the prior art ... |
|
| Magnetic field sensor on elemental semiconductor substrate with electric field reduction means |
| It is, therefore, an object of this invention to provide a magnetic field sensor of an indium ... |
|
| Method of preparing InSb thin film |
| An object of the present invention is to provide a method of preparing an InSb thin film, which can ... |
|
| Organometallic fluorescent complex polymers for light emitting applications |
| The above described problems and others are at least partially solved and the above purposes are ... |
|
| Method and apparatus for manufacturing semi-insulation GaAs monocrystal |
| Accordingly, it is the object of the present invention to provide a method of manufacturing a semi-... |
|
| Semiconductor luminous element with light reflection and focusing configuration |
| OF THE INVENTION FIG. 1 (a) shows a cross section of semiconductor luminous element A, a surface-... |
|
|
Vibratory transducer
| Details |
Inventors: Ikeda, Kyoichi; Watanabe, Tetsuya; Higashino, Yasushi;
Assignee: Yokogawa Electric Corporation (Tokyo, JP)
Primary Examiner: Woodiel; Donald O.
Assistant Examiner:
Attorney, Agent or Firm: Kojima; Moonray
A vibratory transducer comprising a vibratory beam composed of an n-type layer and having at least one end fixed. The vibratory beam is formed by selectively etching an n-type layer formed by adding impurities locally to a single silicon crystal. The vibratory transducer also comprises means for vibrating the vibratory beam and means for detecting vibration of the vibratory beam. The vibratory transducer measures pressure, temperature, density, etc, by detecting change in the resonant frequency of the vibratory beam. The vibratory beam can be finely etched irrespective of the density of the impurities therein by forming the vibratory beam in an alkaline aqueous solution while applying a negative DC or pulsed voltage to a p-type layer and a positive DC or pulsed voltage to an n-type layer. The vibrating and detecting means for the vibratory beam can be easily provided by making a diode and a transistor including the vibratory beam in the transducer. |
|
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Turning now to FIGS.
4-7, which depicts a first illustrative embodiment of the invention, there is depicted a single silicon crystal 30 of the p-type containing impurities at a density of pb 10.
sup.
15 or 10.
sup.
17 atoms/cm.
sup.
3 or less.
A diaphragm 31 is formed by etching silicon substrate 30.
An n.
sup.
+ diffused layer 32 is formed locally on the surface of diaphragm 31 by adding impurities at a density ranging from 10.
sup.
17 to atoms/cm.
sup.
3.
The p layer of diaphragm 31 is underetched except for a surface portion of n.
sup.
+ diffused layer 32, thus forming a vibratory beam 34 composed of an n.
sup.
+ layer.
Vibratory beam 34 is disposed above a recess 35 and is supported at two spaced points.
Piezoelectric elements (such as of ZnO) 36, 36a, are disposed near the supported points of vibratory beam 34, and are each in the form of a thin film having a thickness of about 1 micrometer.
Electrodes 37,37a, serve to vibrate piezoelectric elements 36,36a, respectively, and are connected by leads (not shown) to an external circuit (not shown) in insulated relation to the p layer of diaphragm 31 and vibratory beam 34.
An SiO.
sub.
2 layer 38 having a thickness of about 4 micrometers is formed on diagrphram p layer 31 by chemical vapor deposition (CVD) and has an opening or space 33 above vibratory beam 34.
A silicon cover 39 having a thickness of about 5 micrometers, for example, is made of the same material as diaphragm 31.
Silicon cover 39 and SiO.
sub.
2 layer 38 on diaphragm 31 are connected by anodic joining in vacuum to evacuate an area in which the vibratory beam is formed.
One illustrative example of the dimensions of vibratory beam 34 is as follows.
Thickness h is 2 micrometers.
Length L is 200 micrometers.
Width d is 5 micrometers.
The resistance to a static pressure on the area in which vibratory beam 34 is formed can be attained by suitably increasing the ratio l.
sub.
4 /l.
sub.
3 of the width 2l.
sub.
3 of the hole shown in FIG.
6 and the thickness l
|
|
Active Solid-state 
