Rudolph Technologies,
Inc. (NASDAQ: RTEC), a worldwide leader in process characterization solutions
for the semiconductor manufacturing industry, announced today that it has recently
received an order for its MetaPULSE®-III thin film metrology tool to be
used for measuring copper barrier, seed, and pre-and post-CMP fill layers in
high-volume production at a major memory fab in Asia. The selection followed
a six month on-site evaluation, and was based on the unique ability of the new
MetaPULSE-III to measure films on product wafers with high precision and low
cost of ownership. This same major Asian memory manufacturer also recently ordered
an additional MetaPULSE tool for in-line process control of aluminum films.
“We are, of course, very pleased to win this new business in such an
important, leading-edge application,” said Jack Kurdock, vice president
and general manager of Rudolph’s Metrology Business Unit. “Copper
barrier and seed layers have reached thicknesses that can be very challenging
to measure precisely. Using a newly developed technique that simultaneously
extracts information from multiple detectors, the MetaPULSE-III demonstrated
superior speed and repeatability on these ultra-thin films. Its small spot size
permits measurements within die on product wafers which allows for real-time
feedback of pre-and post-CMP copper film thickness in the active area, providing
an early indication of device performance. This, along with the repeat order
received for the Al-based process applications, reaffirms MetaPULSE as the tool-of-record
for production monitoring of opaque film thickness.”
The thicknesses of the barrier and seed layers, which are deposited in vias
and lines to prevent copper migration and promote uniform nucleation for the
subsequent copper fill, are among the smallest and, therefore, most difficult
to control dimensions in current device designs. At the 32 nm node, barrier
layer (Ta/TaN) thicknesses range from 5 nm to 7.5 nm and seed layer thicknesses
from 10 nm to 20 nm. The MetaPULSE System provides a gauge-capable metrology
solution for these thin barrier/seed layers in addition to in-die measurement
of electroplate and post-CMP copper. It uses an ultra-fast flash of laser light
to generate a sound wave that passes through the film stack. When the sound
wave encounters a film interface, an echo returns to the surface. The time between
sound induction and echo detection provides a direct measurement of film thickness.
The technique can measure thickness, density and other film parameters of multilayer
stacks non-destructively and without interference from underlying layers.