Advanced plasma technology in microelectronics

The current status and future trends of plasma technology for microelectron ics are discussed. The low pressure high density plasma (HDP) source is adv antageous for the etching of a gate electrode and a small deep contact hole . However, the high temperature electrons in the HDP may induce profile def ects, 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 UL SI, was etched in a magnetically enhanced reactive ion etching (MERIE) plas ma. 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 reac tion with a phase-controlled pulse plasma. The chemistry C4F8/CH3F/Ar was s hown 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 applica tion of HDP-CVD oxide to the trench isolation and the intermetal dielectric s (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 pro perties even after high temperature stressing at 350 degrees C for 100 h. ( C) 1999 Published by Elsevier Science Ltd. All rights reserved.