1. Field of the Invention
The present invention relates to a method of manufacturing a device for performing a dicing in such a way that a substrate, on which two or more devices and alignment marks for positioning are formed, is positioned in accordance with the alignment mark, a positioning method, and dicing method and dicing apparatus in which the substrate is separated through the dicing to individual device elements equipped with individual devices.
2. Description of the Related Art
Hitherto, to perform a dicing for a device substrate in which two or more devices, such as semiconductor wafers, are made, generally, there is adopted such a process that the device substrate is fixed on a dicing table through putting the device substrate on an adhesive dicing tape, the device substrate is subjected to the dicing processing so as to be segmented into device elements referred to as a chip, and the device elements are picked up one by one from the dicing tape.
However, a state-of-the-art device including MEMS (Micro Electro Mechanical Systems) device, on which the research is advanced, has an extremely minute structure. Thus, when the device elements are picked up from the adhesive tape, the structure is damaged. This involves a problem that the yield is extremely low.
In order to improve this problem, there is proposed a method in which a device substrate is wrapped with the coagulant, without the use of the adhesive tape, and the coagulant is coagulated, so that the device substrate is fixed (cf. Japanese Patent Publication TokuKai. Hei. 10-230429, and Japanese Patent Publication TokuKai. Hei. 11-309639).
However, fixing of the device substrate by the coagulation of the coagulant involves a problem of a difficulty of positioning of the device substrate. For the dicing for the device substrate, there is a need that the device substrate is exactly positioned relatively to a dicing blade. To perform the positioning, when devices are made on the device substrate, an alignment mark is formed at a position determined exactly as to the devices, and the alignment mark is photographed by a camera, so that the positioning is carried out based on the alignment mark on the image. However, when the coagulant is coagulated, the coagulation brings about a state that the coagulant is opaque or light scattering. Thus, it is difficult for a camera to recognize the alignment mark. Before the coagulation of the coagulant, it is easy for the camera to recognize the alignment mark. However, the position may be shifted in the process in which the coagulant is coagulated, and thus the recognition of the alignment mark before the coagulation would not be useful for positioning.
It is considered that the device substrate is fixed with a material liquid with viscous high in place of the coagulant. In this case, it is possible to recognize the alignment mark. However, as compared with a case where a position is fixed by coagulation of the coagulant, the position of the device substrate changes easily. And, the dicing for the device substrate is carried out while the coolant such as the pure water is sprayed for cooling and the removal of the cutting powder. However, even if the device substrate is covered with a liquid material of high viscosity, the device substrate is pressured by spraying of the coolant, and as a result, the device will be damaged. This involves a problem that the yield is not sufficiently improved.
Japanese Patent Publication TokuKai. Hei. 6-331813 discloses a technology in which the substrate that forms the diffraction grating is put in the water tank that fills the pure water, and the pure water is frozen to fix the substrate and then subjected to cutting. This also easily brings about opaque or light scattering state at the time of freezing. Thus, according to the technology disclosed in Japanese Patent Publication TokuKai. Hei. 6-331813 too, it is difficult to perform a positioning base on the alignment mark.
Further, according to the second type of extended library apparatus show in FIG. 21, there are provided the same number of moving mechanisms as the number of coupled library apparatuses. Thus, as compared with the first type of extended library apparatus show in FIG. 19, which is capable of coping with coupling of a plurality of library apparatuses with one moving mechanism, it involves problems of high cost and increment of dissipation power.