화학공학소재연구정보센터
Thin Solid Films, Vol.341, No.1-2, 112-119, 1999
Advanced plasma technology in microelectronics
The current status and future trends of plasma technology for microelectronics are discussed. The low pressure high density plasma (HDP) source is advantageous for the etching of a gate electrode and a small deep contact hole. However, the high temperature electrons in the HDP may induce profile defects, notch and sidewall etching, and may degrade the electrical duality of the gate oxide. By lowering the electron temperature with the pulse plasma technique, the etch profile of the gate electrode was improved. Platinum, the suggested storage electrode for the capacitor of the next generation ULSI, was etched in a magnetically enhanced reactive ion etching (MERIE) plasma. With the etching chemistry of Cl-2/O-2/Ar, it was etched with the slope of up-to 80 degrees. In SiO2 etching, the HDP is advantageous for less RIE-lag. We also need to control the polymerization for the critical dimension (CD) control and for the selectivities to the resist, silicon, and also to Si3N4 for the self-aligned contact (SAC). It was shown that it is possible to control the dissociation of radicals in the plasma and the surface reaction with a phase-controlled pulse plasma. The chemistry C4F8/CH3F/Ar was shown to achieve the requirements for the SAC hole etching, but the process window was quite narrow. Also, the HDP-CVD SiO2 and SiOF have shown better gap filling capability, film quality and more favorable deposition profiles than conventional CVD oxides. We also discussed the results of the application of HDP-CVD oxide to the trench isolation and the intermetal dielectrics (IMDs). The him characteristics of fluorine doped HDP-CVD SiO2 (SiOF) as a low dielectric material was found to be very stable with uniform film properties even after high temperature stressing at 350 degrees C for 100 h.