METHOD FOR PLASMA DICING A SEMI-CONDUCTOR WAFER
FIG2 is a cross-sectional view of a semiconductor substrate illustrating individual devices separated by streets
In the present invention, as is shown in a cross sectional view in FIG2, the device structures (110) are then covered with a protective material (200) while the street areas (120) remain unprotected. This protective material (200) can be a photoresist, applied and patterned by well-known techniques. Some devices, as a final process step are coated with a protective dielectric layer such as silicon dioxide or PSG which is applied across the whole substrate. This can be selectively removed from the street areas (120) by patterning with photoresist and etching the dielectric material, as is well known in the industry. This leaves the device structures (110) protected by the dielectric material and the substrate (100) substantially unprotected in the street areas (120). Note that in some cases test features to check the wafer quality may be located in the street areas (120). Depending on the specific wafer fabrication process flow, these test features may or may not be protected during the wafer dicing process. Although the device pattern illustrated shows oblong die, this is not necessary, and the individual device structures (110) may be any other shape, such as hexagons, as best suits the optimum utilization of the substrate (100). It is important to note that while the previous example considers dielectric materials as the protective film, that the invention may be practiced with a wide range of protective films including semi-conductive and conductive protective films. Furthermore, the protective layer can consist of multiple materials. It is also important to note that some portion of the protective film may be an integral part of the final device structure, (e.g., a passivation dielectric, metal bonding pad, etc.). Furthermore, the present invention can also be beneficially used with bulk wafers without the necessity of having devices or device structures. One such example may be a semiconductor substrate (Silicon, III-V compounds, etc.), mounted on a carrier or not mounted, covered by a masking material defining the structures to be etched. The substrate may also contain at least one additional layer with different material properties, such as for example an insulating layer.
cross-sectional view
100
substrate substrates
2
approximately than
110
device structures
200
protective material
120
areas
['1. A method for plasma dicing a substrate (100), the method comprising: - providing a process chamber (600) having a wall; - providing a plasma source (620) adjacent to the wall of the process chamber (600); - providing a work piece support (630) within the process chamber (600) ; - providing an electrostatic chuck (670) within said work piece support (630), said electrostatic chuck (670) having a plurality of gas inlet ports (1710) ; - providing a lift mechanism (680) within the process chamber (600) ; - loading a work piece (320) onto said work piece support (630) using said lift mechanism (680), said work piece (320) having a support film (300), a frame (310) and the substrate (100), said lift mechanism (680) engaging said work piece (320) outside an outer diameter of the substrate (100) of said work piece (320) and at least one of said gas inlet ports (1710) is positioned outside of said outer diameter of the substrate (100) of said work piece (320); - electrostatically clamping said work piece (320) to said work piece support (630) using said electrostatic chuck (670); - generating a plasma (400) using the plasma source (620); and etching the work piece (320) using the generated plasma (400).']