 System for group leader recovery in a distributed computing environment |
| The shortcomings of the prior art are overcome and additional advantages are provided through the ... |
|
| Method of multicast file distribution and synchronization |
| This invention presents a method that delivers arbitrary data from a single source node, known as a ... |
|
| Color video and audio recording and/or reproducing apparatus |
| Accordingly, it is an object of the present invention to provide an apparatus, such as, a VTR, for ... |
|
| Optical information recording method |
| A first object of this invention is to provide a method of realizing a high erasability when a ... |
|
| Multi-channel echo canceler and method using convolution of two training signals |
| OF THE DRAWINGS In the preferred embodiments, the present invention provides, among other things, ... |
|
| Shared memory multiprocessor performing cache coherency |
| In the case of constructing a switch type SMP and further dividing the interior of the SMP into ... |
|
| Apparatus and methods for modulation and demodulation of data |
| The present invention seeks to provide improved methods and apparatus for modulating and ... |
|
| Method for transmitting multimedia packet data using a contention-resolution process |
| The present invention is based on a technique wherein packets received at a receiving port of a ... |
|
| Insulated gate field-effect transistor read-only memory array |
| Applicant has discovered that the phenomenon of hot electron trapping may be utilized to fabricate ... |
|
|
Ion-beam etching method and an apparatus therefor
| Details |
Inventors: Konishi, Fumiya; Kusao, Kenji; Yoshioka, Yoshiaki;
Assignee: Matsushita Electric Industrial Co., Ltd. (Kadoma, JP)
Primary Examiner: Dixon; Harold A.
Assistant Examiner:
Attorney, Agent or Firm: Wenderoth, Lind & Ponack
The present invention enables a decrease in etching velocity in an ion-beam etching system without decreasing the current density of the ion beam. The ion-etching is performed at a constant value of ion-beam current density and an increased partial pressure of oxygen or other suitable gas in the specimen chamber. The partial pressure of oxygen is increased until the intensity of a secondary ion-beam from the specimen reaches a saturation value. Under these conditions a stable reduced etching velocity is obtained, the value of which is determined by the ion-beam current density, the partial pressure of oxygen and the previously determined characteristics of the specimen. |
|
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Hereinafter, details of an embodiment of the present invention will be described.
In the specimen chamber for holding therein a specimen to be etched, a gas inlet valve for introducing gas into the specimen chamber and a secondary ion monitor for monitoring secondary ions from the specimen are installed.
Ion beam etching is performed by increasing the partial pressure of oxygen in the specimen chamber while keeping the current density of the ion beams constant, as shown in FIG.
2.
Then, the etching velocity decreases as the intensity of the secondary ion is increased and saturated to a definite value.
This phenomenon is utilized.
Thus, it becomes possible to decrease the etching velocity, allowing only a small amount of the gas of one type to be adsorbed on the specimen surface without decreasing the current density, and also to achieve stable and easy control of the constant etching velocity.
In this instance, the gas pressure which causes the change in the etching velocity should be varied with the type of the material to be etched and with the current density of the ion beam, and if numerous types of stable oxides exist, as is the case with some metals, the etching velocity and the intensity of the secondary ion undergo changes in two or three steps.
Referring to FIG.
2, the present invention includes the following structures in addition to those found in the prior art as illustrated by FIG.
1; numeral 19 designates a secondary ion drawing-out system; 20, a mass separator; 21, a detector; 22, the secondary ion monitor; 23, a gas inlet section; 24 and 25, slits; and 26, a vacuum exhaust system.
Through the gas inlet section 23 attached to a specimen chamber 13, high purity gas such as oxygen or the like is introduced, up to a gas pressure of 1 .
times.
10.
sup.
-5 Torr.
If this introduced gas is allowed to diffuse to the ion beam focusing section, the field of the static type lenses is altered; then, the current density changes and the beam diameter fluctuates, and as a consequence, the etching velocity can not be kept constant
|
|
CPUs 
