AVS 47th International Symposium
    Plasma Science and Technology Friday Sessions
       Session PS-FrM

Paper PS-FrM11
Planar-Antenna Structure UHF-ECR Plasma for Highly Selective Insulator Film Etching

Friday, October 6, 2000, 11:40 am, Room 310

Session: Dielectrics II
Presenter: K. Yokogawa, Hitachi, Ltd., Japan
Authors: K. Yokogawa, Hitachi, Ltd., Japan
M. Izawa, Hitachi, Ltd., Japan
S. Yamamoto, Hitachi, Ltd., Japan
N. Negishi, Hitachi, Ltd., Japan
Y. Momonoi, Hitachi, Ltd., Japan
H. Kawahara, Hitachi, Ltd., Japan
M. Kojima, Hitachi, Ltd., Japan
K. Tsujimoto, Hitachi, Ltd., Japan
S. Tachi, Hitachi, Ltd., Japan
Correspondent: Click to Email
We developed an ultra-high-frequency ECR plasma (UHF-ECR) etching system with a planar-antenna structure for the etching of insulator film. We believe that high precision radical control, CF@sub 2@/F ratio and CF@sub 2@/ion ratio control of fluorocarbon plasma, is an important for etching of insulator film with highly selective and fine feature control for below 0.13 µm design rule ULSI devices. UHF-ECR has a function of the radical control that is achieved by the plasma gap control for reduction of source gas dissociation and the double-near-surface effect @footnote 1@ for radical changes. A 450 MHz UHF wave was supplied to a planar-antenna located on the opposite side of a wafer. The magnetic field for ECR was supplied by solenoid coils, and distance between the planer-antenna and ECR plane was 5-20 mm. Stable plasma in a wide density range between 10@super 11@ and 10@super 12@ /cm@super 3@ was formed at pressure range between 1 and 50 mTorr. The plasma was uniform within ±3% up to a diameter of 200 mm, and the plasma distribution on the wafer was controlled by the magnetic-field distribution. The SiO@sub 2@ film etching was carried out by UHF-ECR plasma with C@sub 4@F@sub 8@ based gases. We confirmed that the increasing of CF@sub 2@/F ratio can be achieved by the plasma gap reduction using optical emission spectroscopy. We obtained self-aligned-contact etching with selectivity of 25, and high-aspect-ratio-contact hole etching (0.13 µm, aspect ratio: 14) with etching rate above 700 nm/min. High selectivity and high feature control ability were also demonstrated with low-k films such as organic SOG film and organic film. @FootnoteText@ @footnote 1@ S.Tachi, M.Izawa and M.Kojima; 1997 Proceeding of dry process sympo. p.83-90.