A coil assembly includes a spool having a wire wound therearound to establish a coil. At least one allocation policy is assigned to the file, wherein the allocation policy specifies one or more storage units on which the blocks are to be allocated. The said unit shelf not only can provide an easy space control to another unit shelf neighboring along front and rear support frames but also can fix set positions by using a stopper and can be separated conveniently by using a separation device. When the transparent siloxane resin produced by a non-hydrolytic reaction forms a composite in combination with the glass filler, the composite realizes high transparency and heat resistance, as well as a low thermal expansion coefficient. The support members are disposed inside the jacket so that they are equally balanced in the peripheral direction of the jacket. In a step of forming a gettering site, a plasma CVD method is used and a film formation is conducted using raw gas including monosilane, noble gas, and nitrogen to obtain a semiconductor film which includes the noble gas element at a high concentration, specifically, a concentration of 1\xd71020cm3 to 1\xd71021cm3 and has an amorphous structure, typically, an amorphous silicon film.