ION BEAM PROCESSING APPARATUS AND
SPECIMEN REPLACING METHOD FOR THE
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an ion beam processing apparatus which allows the operation of specimen replacement on the specimen holder to be performed 10 automatically, and to a specimen replacing method for such an ion beam processing apparatus.
2. Description of the Related Art Conventional ion beam processing apparatuses, as
disclosed in, for example, Japanese Patent Laid-Open 15 No. 53-23843 and 61-18132, include a specimen turning mechanism for turning a specimen holder in a vacuum vessel around a center axis and a specimen holder tipping mechanism for tipping the specimen holder, thereby enabling a uniform irradiated with an ion beam. 20
In an ion beam processing apparatus, it is necessary to cool the specimen while the specimen is processed and, for this purpose a cooling method has been proposed in Japanese Patent Laid-Open No. 56-48132, wherein .the specimen holder is provided with flow passages, 25 through which cooling water or cooling gas flows, thereby cooling the specimen from behind.
In the prior-art techniques mentioned above, the specimen is secured to the specimen holder by locking the outer periphery of the specimen by screws or the 30 like, so that only manual replacement of specimen is possible.
Further, to adequately cool the specimen by cooling water or cooling gas flowing on the specimen holder, the specimen must be placed in close contact with the 35 surface of the specimen holder. Thus, manual replacement of the specimen is necessary.
A problem with the manual replacement of the specimen resides in the fact that the vacuum vessel must be opened to atmospheric air each time a specimen re- 40 placement is performed. Once the vacuum vessel has been opened, it usually takes about 30 to 60 minutes to re-create a vacuum of the same level as before, thereby substantially reducing productivity. Moreover, a manual replacing operation is rather difficult to perform 45 and, is time consuming.
SUMMARY OF THE INVENTION
It is an object of this invention to provide an ion beam processing apparatus and a specimen replacement 50 method wherein the replacement of a specimen is automated thereby making it possible to perform the replacing operation without opening the vacuum vessel to atmospheric air.
To achieve the above object, according to the present 55 invention an ion beam processing apparatus comprises an ion source for generating ions, with a vacuum vessel being provided for extracting ions from the ion source to process specimens. A conveying mechanism feeds and extracts specimens to and from the vacuum vessel 60 to effect specimen replacement, with a specimen holder, provided in the vacuum vessel, holding a specimen while the specimen is processed, and with a raising/lowering means for raising and lowering the specimen holder at the time of specimen replacement. 65
In accordance with further features of the present invention, may further comprise a specimen turning mechanism for turning the specimen holder around a
central axis, with a specimen tipping mechanism tipping the specimen holder.
The specimen holder is equipped with a locking means for locking specimens with the locking means being adapted to lock a specimen on the specimen holder by the biasing force of springs.
The above-mentioned raising/lowering means may include a spiral groove formed on the outer peripheral surface of a slide table supporting the specimen holder and a pin fastened to the ion-beam-apparatus body and engaging the above groove. By turning the slide table, raising/lowering means can be raised and lowered.
The above-mentioned slide table may turned by a stepping motor or manually.
In accordance with the present invention specimen replacement method of the present invention, a specimen holder holding a specimen which has been processed thereon by an ion beam is raised with the processed specimen being transferred to a conveying mechanism. A specimen which has not been processed and which has been conveyed by the conveying mechanism is transferred to the specimen holder, and the specimen holder is lowered to complete a specimen replacement.
In accordance with further features of the specimen replacement method of the present invention, catch rods supporting a periphery of a specimen which has been processed on a specimen stage by an ion beam are raised thereby raising the specimen, with an arm of a conveying mechanism being brought to a position below the specimen thus raised. The catch rods are lowered to transfer the processed specimen to the arm, and the conveying mechanism is driven to bring the arm, which now holds an unprocessed specimen, to a position above the catch rods. The catch rods are raised to raise the unprocessed specimen and causing the arm to retreat, and the catch rods are lowered to place the unprocessed specimen on the specimen stage.
With the above arrangements, specimen replacement can be automatically effected in the vacuum vessel by raising and lowering the sample holder by the raising/lowering means when transferring to the sample holder a specimen which has been conveyed by the conveying mechanism or transferring the processed specimen to the conveying mechanism. Thus, specimen replacement can be performed without opening the vacuum vessel to the atmospheric air.
Further, since the specimen on the specimen holder is locked by the locking means, the specimen is perfectly secured in position while it is processed by an ion beam, thus making it possible to effect a uniform processing.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view, taken along the line II—II of FIG. 2, of a specimen holder in accordance with the present invention;
FIG. 2 is a schematic view of a general construction of the ion beam processing apparatus of the present invention;
FIG. 3 is a front view of the slide table of the apparatus of the present invention; and
FIG. 4 is a sectional view of a specimen holder in accordance with another embodiment of the present invention.