349 mm atmospheric linear type plasma source for 12-inch semiconductor surface processing

Plasma irradiation is commonly used for hydrophilic bonding in semiconductor heterogeneous material integration. In this treatment, it is difficult to perform sequential processing, since the plasma is irradiated to semiconductor wafers under low pressure. To solve this, plasma irradiation should be carried out under atmospheric pressure, and up to now an atmospheric multi-gas plasma jet have been developed in our laboratory. Atmospheric plasma with various gas was generated by this device, and high hydrophilization was obtained on silicon surface treating. However, since the diameter of plasma injection hole of the device is 1 mm, two-axis scanning is required to treat a silicon wafer. In this study, an atmospheric linear type plasma source was developed to treat a 12-inch silicon wafer with one-axis scanning. This source has an irradiation slit of 1 mm x 349 mm and can irradiate plasma like gas curtain. Stable argon and helium plasma was generated by applying 13.56 MHz to the electrode and flowing plasma generating gas at a rate of 20 L/min. To enhance the treatment effect, plasma with mixing nitrogen or oxygen to argon was also generated. To evaluate hydrophilic effect over large areas, the copper plate was scanned by linear type plasma at scan speed of 4 mm/s. Result showed the water contact angle was decreased more than 60 degrees from 102 degrees by mixing 10% nitrogen to argon. In the presentation, relationship between the RF power and the treatment effects will be presented.