Date Visited: October 11, 1991
Report Author: M. Thompson
The name Anelva is derived from Analysis, Electronics, Vacuum.
Anelva was formed in 1967 as a joint venture between NEC (51%) and Varian (49%); it was then called NEVA. In 1985, it became wholly owned by NEC, with a substantial business (32 billion yen) in semiconductor equipment and vacuum instruments. It has had substantial revenue growth, with sales of 53 billion yen in 1991.
It is organized into six business units:
The main focus of the discussion was on their PECVD machines used in TFT production. Anelva has 80% of worldwide market for PECVD machines and 30-40% of the Japanese sputtering market. It is developing plasma etching.
Anelva's biggest system has eight chambers, costs approx. $5M, and has a 9-month lead time for delivery. Film uniformity is +/- 10% for a-Si & Si3N4 on their ILV-9330E machine. The tact time of their system is 10 mins. Contamination issues have a strong influence on tact time because of degassing issues. The systems have easy access for cleaning.
Particulate contamination in PECVD causes a major yield issue. It is difficult to measure, but they are successful in measuring particulate in the vacuum ports of the load and unload chamber using light-scattering laser detectors.
Downtime of machines in manufacturing is a major issue. They allow the chambers to cool and sand blast the coated parts. They have tried plasma cleaning at the chamber operating temperature, but it was not successful. The film quality was poor immediately after plasma etching and only recovered to device quality after 10 hrs. of deposition. Downtime of the machine depends on users but is often 30 hrs. The frequency of cleaning varies with the users from 3 days to 2 weeks. The substrate holders and frames are regularly cleaned. The shower plate contributes most to flaking and particle generation.
Particle levels are not guaranteed in their machine, but after cleaning they have measured 50-100 particles of <0.3 micron on a 4-inch wafer.
In the preheat chambers, lamp heating is used; in the cooling chamber, water cooling is used, with convection cooling with H gas. The substrates are removed from the system at 150 degrees centigrade and they cool in the return path tunnel to 70-80 degrees centigrade.
They use a simple hinged window frame substrate holder. They are not entirely happy with the automated substrate loading system.
As to the choice of machine size and number of machines, they recommend 2-3 machines per line (rather than 1 big machine) to obtain optimum productivity.
For etching, they will use a single substrate system with 2 or 3 reaction chambers. ITO is DC sputtered in Ar/O2 atmosphere.
They believe the life of their machine is 7 years.
Their main competitors are Shimazu in PECVD and Ulvac and Leybold in sputtering. They confirmed that one company is using dry etch only (no wet etch apart from ITO).