RE-Al™ PLUS

…now with even longer life and lower Cost of Ownership

Introduction

Applied Materials’ The RE-Al™ PLUS is a further enhancement to Praxair MRC's original RE-Al™ design. The dual ring configuration is optimized for lifetime extension up to 100% over standard monolithic Endura targets. The RE-Al™ PLUS target has demonstrated the capability to produce more than 9000 1-µm films.

The RE-Al™ PLUS monobloc sputtering target, Figure 1, as used in Applied Materials Endura™ PVD systems has been developed in response to customer and OEM requests for significant life extension and improved uniformity. The goal was to design targets capable of producing more than 8000 1-µm films independent of the number of kilo-watt-hours (kWh) required.


Figure 1. The RE-Al™ PLUS
In tests, the new RE-Al™ PLUS design (patent pending) developed by MRC has demonstrated the ability to produce more than 9000 1-µm films in 1650 kWh of operation, exceeding the requirements of the market.

The RE-Al™ PLUS:

The RE-Al™ PLUS is a further enhancement to Praxair MRC's original design, the RE-Al, introduced more than 2 years ago. The dual ring configuration now has a thicker outer and thinner inner enhancement. The RE-Al PLUS target is rated at 9000 1-µm films.

The RE-Al PLUS is made from Al alloys processed with MRC's long established CCHTM technology. There is no change in the metallurgical structure (grain size, crystallographic orientation, purity, etc.) from our standard Al alloy targets.

RE-Al™ PLUS Performance:

Tests were conducted utilizing a Durasource™ cathode with an A-type magnet configuration in an Applied Materials Endura™ PVD system. Large 12.75" diameter, Al/0.5Cu wt% Cu RE-Al PLUS Monobloc targets for 8" wafers were tested . Sputtering conditions were 2.5 mTorr Ar pressure, wafer temperature of 300C, a constant deposition rate of 180 A/s and no substrate bias.

Film Uniformity

MRC has demonstrated, that this target can be run at a fixed spacing throughout target life, while maintaining uniformity at or below 4% 3 (1.33% 1-). Our tests showed that a target-to-substrate (T-S) spacing of between 47 and 49 mm worked well, Figure 2. However, it is still recommended that customers optimize the spacing for their tools using a spacing matrix during target qualification. The RE-AL PLUS further optimizes the ring enhancement design so as to improve film uniformity by controlling the film center thickness.


Figure 2. 2D response surface for uniformity as a function of kWh and T-S spacing. The solid red line indicates the constant spacing T-S spacing for best uniformity

Number of 1-µm films

The RE-Al PLUS is rated at 9000 1-µm films or 1650 kWh. This performance enables the RE-Al PLUS to meet all of the current operational requirements for the various equipment configurations used in the Endura™ sputtering tool including the ESC (electrostatic chuck) and clamp ring. Figure 3 illustrates the lifetime extension and the greater number of films that can be produced with the RE-Al PLUS.


Figure 3.Films through kWh of life

Sputter Rate

The RE-Al™ sputters very efficiently. The high deposition rate enables users to obtain high wafer counts at a lower number of kWh. This enables operators to process more wafers for a given number of kWh as compared to other designs. Because of the higher rate, operators may reduce the amount of power or time required to deposit a film of a given thickness. In either case, the cumulative kWh builds up at a slower rate than standard or competitive designs.

Benefits of RE-Al PLUS targets

The Cost of Ownership benefits derived from the use of the Praxair MRC RE-Al PLUS targets are:

  • High wafer counts
  • Greater Productivity
  • Excellent Uniformity
  • Ease of Operation

The RE-Al PLUS provides semiconductor producers an ideal avenue to reduce costs and increase productivity. Based upon the users kit change frequency, one can see in Table 1, right, that there is a reduction in the number of targets required between 25 and 50%.


Table 1. Target lifetime extensions and reductions in targets required meeting production needs.

This translates into:

  • up to 40% reduction in out of pocket expenditures
  • up to 50% reduction in cost per mm or wafer pass

Coupling this with the added benefits of fewer target changes and greater tool availability, the RE-AL™ PLUS is an industry leading design for low cost sputtering production.

Summary

The RE-Al PLUS is an exciting development from the initial RE-Al design launched 2 years ago. It builds upon the strength and proven benefits of the RE-Al concept. The RE-Al PLUS allows customers to run their targets up to 1650 kWh and produce over 9000 1-µm films. This enhanced productivity will bring considerable CoO benefits to the wafer fab over and beyond the standard Endura™ monolithic design.

For more information, Praxair MRC sales engineers are available to review target performance, film quality and cost of ownership improvements based upon you specific requirements.

   
 

CCH Process
CCH Do Aluminum Alloys
CCH Do and Do* Ti
Co and Ni
Ta and Cu

Thin Films Application Lab
Bonding Technology
Novellus Inova™ Tool
Endura™ & Centura™ Systems
RE-Al Plus": Sputter Targets
Technical Papers  
  1. Reduction of TiN Nodule Density Through Optimization of Cathode and Process Variables
  2. Effect of Oxygen Content on Particle Generation in TiN Reactive Sputtering
  3. Link From Titanium Target Orientation to Titanium/Titanium Nitride/Aluminum Thin Film Orientations
  4. Technical Papers Available in PDF