Title :
In-line copper process control using picosecond ultrasonics
Author :
Stoner, Robert J. ; Morath, Christopher J. ; Tas, Guray ; Trofimov, Igor ; Kahlert, Volker
Author_Institution :
Div. of Eng., Brown Univ., Providence, RI, USA
Abstract :
We have made noncontact thickness measurements using picosecond ultrasonics for a series of electrochemically deposited (ECD) copper films, and for a series of PVD copper films deposited on thin films of Ta. For the PVD Cu-Ta bilayers, the thicknesses of both films were obtained simultaneously within the same measurement. The measurement area was less than 30 μm in diameter. The measurements were found to be in close numerical agreement with TEM measurements. The results also show that the thickness measurements for all films are highly linear as a function of deposition time, and highly repeatable
Keywords :
copper; diffusion barriers; electroplating; integrated circuit interconnections; integrated circuit measurement; integrated circuit metallisation; process control; sputter deposition; thickness measurement; transmission electron microscopy; ultrasonic applications; ultrasonic measurement; 30 micron; Cu-Ta; ECD copper films; PVD Cu-Ta bilayers; PVD copper films; TEM measurements; Ta; Ta thin films; deposition time; electrochemically deposited copper films; in-line copper process control; measurement area; noncontact thickness measurements; repeatable measurements; simultaneous dual film thickness measurement; thickness measurements; ultrasonics; Atherosclerosis; Copper; Electrical resistance measurement; Optical films; Optical pulses; Optical surface waves; Process control; Pulse measurements; Thickness measurement; Ultrasonic variables measurement;
Conference_Titel :
Interconnect Technology, 1999. IEEE International Conference
Conference_Location :
San Francisco, CA
Print_ISBN :
0-7803-5174-6
DOI :
10.1109/IITC.1999.787069
