By using a high purity target as a target, using a single gas, argon, as a sputtering gas, setting the substrate temperature at 300\xb0 C. The gate electrode is used as a mask during ion doping for forming an LDD. The overall performance provides the capability of advantageous modulation beyond the conventional 100% modulation limit. The apparatus further includes a connectingseparating portion for removably connecting the dust barrel in the dust chamber to the lower end of the cyclone body. Specifically, the intra-cavity filter material in combination with the cavity length controller, allow a mode of cavity to be located at the filter function. Different configurations or shapes can be utilized for the sides of the bar to vary the turning characteristics between left and right turns.