Longarmmanipulatorforstandardmechanicalinter.docx

1、LongarmmanipulatorforstandardmechanicalinterLong arm manipulator for standard mechanical interface apparatusCROSS REFERENCE TO RELATED APPLICATIONSThe following commonly assigned applications relate in general to the field of standardized mechanical interface systems. SEALED STANDARD INTERFACE APPAR

2、ATUS; Inventors: George Allen Maney, Andrew William OSullivan, W. George Faraco; Ser. No.: 635,384; Filed: July 30, 1984. BOX DOOR ACTUATED RETAINER; Inventors: George Allen Maney, Andrew William OSullivan, W. George Faraco; Ser. No. 686,443; Filed: Dec. 24, 1984. SHORT ARM MANIPULATOR FOR STANDARD

3、MECHANICAL INTERFACE APPARATUS; Inventors: Anthony Charles Bonora; Ser. No. 769,850; Filed: Aug. 26, 1985. FIELD OF THE INVENTIONThe present invention relates to manipulating apparatus for standardized mechanical interface systems for reducing particle contamination and more particularly to apparatu

4、s transferring cassettes containing articles to be processed into and out of sealed containers suitable for use in semiconductor processing equipment to prevent particle contamination. BACKGROUND OF THE INVENTIONA standardized mechanical interface (SMIF) has been proposed to reduce particle contamin

5、ation by significantly reducing particle fluxes onto wafers. This end is accomplished by mechanically ensuring that during transport, storage and processing of the wafers, the gaseous media (such as air or nitrogen) surrounding the wafers is essentially stationary relative to the wafers and by ensur

6、ing that particles from the ambient outside environment do not enter the immediate internal wafer environment. Control of particulate contamination is imperative for cost effective, high-yielding and profitable manufacturing of VLSI circuits. Because design rules increasingly call for smaller and sm

7、aller lines and spaces, it is necessary to exert greater and greater control on the number of particles and to remove particles with smaller and smaller diameters. Some contamination particles cause process defects, such an incomplete etching in spaces between lines leading to an unwanted electrical

8、 bridge. In addition to such physical process defects, other contamination particles may cause electrical failure due to induced ionization or trapping centers in gate dielectrics or junctions. Modern processing equipment must be concerned with particle sizes which range from below 0.01 micrometers

9、to above 200 micrometers. Particles with these sizes can be very damaging in semiconductor processing. Typical semiconductor processes today employ geometries which are 1 micrometer and under. Unwanted contamination particles which have geometries measuring greater than 0.1 micrometer substantially

10、interfere with 1 micrometer geometry semiconductor devices. The trend, of course, is to have smaller and smaller semiconductor processing geometries. In typical processing environments today, clean rooms are established in which, through filtering and other techniques, attempts are made to remove pa

11、rticles having geometries of 0.03 micrometer and above. There is a need, however, to improve the processing environment. The conventional clean room cannot be maintained as particle free as desired. It is virtually impossible to maintain conventional clean rooms free of particles of a 0.01 micromete

12、r size and below. The main sources of particulate contamination are personnel, equipment, and chemicals. Particles given off by personnel are transmitted through the environment and through physical contact or migration onto the wafer surface. People, by shedding of skin flakes, for example, are a s

13、ignificant source of particles that are easily ionized and cause defects. Although clean room garments reduce particle emissions they do not fully contain the emissions. It has been found that as many as 6000 particles per minute are emitted into an adjacent one cubic foot of space by a fully suited

14、 operator. To control contamination particles, the trend in the industry is to build more elaborate and expensive clean rooms with HEPA and ULPA recirculating air systems. Filter efficiencies of 99.999% and up to ten complete air exchanges per minute are required to obtain an acceptable level of cle

15、anliness. To minimize process defects, processing equipment manufacturers must prevent machine generated particles from reaching the wafers, and suppliers of gases and liquid chemicals must deliver cleaner products. Most important, a system must be designed that will effectively isolate wafers from

16、particles during storage, transport and transfer into processing equipment. The Standard Mechanical Interface (SMIF) system has been proposed to achieve this goal. The SMIF concept is based on the realization that a small volume of still, particle-free air, with no internal source of particles, is t

17、he cleanest possible environment for wafers. Further details of one proposed system are described in the article SMIF: A TECHNOLOGY FOR WAFER CASSETTE TRANSFER IN VLSI MANUFACTURING, by Mihir Parikh and Ulrich Kaempf, Solid State Technology, July 1984, pp. 111-115 and in the above cross-referenced a

18、pplications. The proposed SMIF system has three main components, namely, (1) minimum volume, dustproof containers are used for storing and transporting wafer cassettes; (2) canopies are placed over cassette ports of processing equipment so that the environments inside the containers and canopies bec

19、ome miniature clean spaces; (3) doors on the containers are designed to mate with doors on the interface ports on the equipment canopies and the two doors are opened simultaneously so that particles which may have been on the external door surfaces are trapped (sandwiched) between the doors. In the

20、proposed SMIF system, a container is placed at the interface port on top of the canopy; latches release the container door and the canopy port door simultaneously. A mechanical elevator lowers the two doors, with the cassette riding on top, into the canopy covered space. A manipulator picks up the c

21、assette and places it onto the cassette port/elevator or other location within the canopy of the equipment. After processing, the reverse operation takes place. The SMIF system has been proved effective by experiments using prototype SMIF components both inside and outside a clean room. The SMIF con

22、figuration achieved a tenfold improvement over the conventional handling of open cassettes inside the clean room. However, due to the space limitations within the canopy of the processing station, the size and configuration of the elevators and manipulators is important. Furthermore it is desirable

23、that the equipment for removing the cassette holding articles to be processed from the standard mechanical interface container be confined to a small space when not in use while providing a long reach to adjacent equipment. SUMMARY OF THE INVENTIONThe present invention is a manipulator for transferr

24、ing a cassette, holding articles to be processed, to and from a container supported at a processing station. The processing station has a cassette port for receiving the cassette when the cassette moves along a central axis extending from outside the processing station, through the cassette port, an

25、d into the processing station. A cassette platform for supporting the cassette is transportable along the axis for transferring the cassette to and from the container along the central axis. A manipulator is provided for transferring the cassette to and from the central axis to a location offset fro

26、m the axis whereby the cassette platform can travel along the axis past the cassette in a bypassing relation. The manipulator includes an arm in an arrangement having a pivot located on and attached to an arm platform. The pivot arm length together with the location of the pivot point on the arm pla

27、tform establishes a mechanism which maximizes the reach from the central axis while still permitting the co-axial loading and unloading, in a bypassing relationship, of the cassette from and to the cassette platform. The present invention maximizes the amount of reach of the cassette which can be co

28、-axially loaded and unloaded from the cassette platform. This long-arm feature is particularly useful when the present invention is adapted to SMIF processing apparatus in a clean room environment where the reach dimension needs to be large. Additional objects and features of the invention will appe

29、ar from the following description in which the preferred embodiments of the invention have been set forth in detail in conjunction with the drawings. BRIEF DESCRIPTION OF THE DRAWINGSFIG. 1 is a perspective view of the manipulator according to the present invention with a simplified depiction of a p

30、rocessing station. FIG. 2 through FIG. 6 are side view drawings of the manipulator according to the present invention used in description of the manipulation of a cassette holding articles to be processed from a SMIF container into the processing station. FIG. 7 is a backview of the manipulator acco

31、rding to the present invention showing a means for transporting the platforms along the shaft. FIG. 8 is a side view drawing of one embodiment of the manipulator according to the present invention having a manipulator arm with a movable pivot point on a carriage on the second platform. DETAILED DESC

32、RIPTIONWith reference to the Figures, a detailed description of preferred embodiment for the present invention is described. FIG. 1 shows a perspective view of the manipulator 1 of the present invention mounted with a simplified depiction of a processing station 2 with which the manipulator 1 is use

33、d. The processing station 2 includes a body 3 in which a processing step is conducted. For instance, when the articles to be processed are semiconductor wafers, the processing station may operate to place a layer of photoresist on the surface of the wafer. Of course, many other processing steps may be a