SEMICONDUCTOR APPLICATIONS

CCH Do Aluminum Alloys

 

Introduction

Praxair MRC has developed its CCH Do technology for the production of Al alloys used for interconnect metallization. These materials are manufactured in a Controlled environment to yield Consistent High performance. The microstructures of our Alloys have been "tuned" for optimal performance. This fundamental technology has been proven across all of today’s batch, sequential and cluster tool sputtering platforms. CCH technology utilizes thermomechanical processing in which the degree of deformation and the thermal treatments have been carefully optimized and controlled for each alloy type and for cathode configuration. The resulting structure of our standard Al alloys is typically fine grained with a near random, or weak cubic orientation. For specific purposes such as enhanced via filling, strongly textured alloys are available.

Microstructure

From an understanding that performance in terms of uniformity, deposition rate, particles and life time are a function of target attributes such grain size, cyrstallographic texture and precipitate distribution, Praxair MRC has developed its CCH Al alloys to meet the demanding requirements of the semiconductor industry.

Figure 1a illustrates the typical texture and fine grain size in an Al/0.5Cu alloy and Figure 1b illustrates a highly textured and the associated fine grain structure of an Al/1Si/0.5Cu alloy

Fig. 1a Ali/0.5Cu alloy with weak (200) texture and fine grain size. Magnification = 100X

Fig. 1b Al/1Si/0.5Cu alloy with strong (220) texture and fine grain size. Magnification = 100X

Second Phase Structure

Praxair MRC focuses on optimizing the distribution of the second phase precipitates in its CCH Al alloys to minimize the precipate size in the resulting deposited films. CCH processing enables the production of alloys with precipate size of less than 150 nm.

STANDARD PROCESSING C C H PROCESSING
Fig. 2 Second phase precipitate control ion Al/Si/Cu alloys

Clean Metal Processing

The production of CCH Al alloys utilizes clean metal processing in order to eliminate "splats" and particles. In Figure 3, below, an ultrasonic C-scan of an sputtered target manufactured using improved casting techniques shows the elimination of inclusions. This translates into elimination of defects on deposited thin film.

Fig. 3 Praxair MRC developed ultrasonic analysis techniques for inclusion analysis shows target materials free of inclusions (left) and the resulting defect-free Al alloy thin film (right).

Summary

Praxair MRC’s CCH Do ALUMINUM ALLOYS meet both wafer fab and OEM tool makers drive for reduced cost of ownership. Optimization of of grain size and texture, second phase precipitate size and distribution and Clean Metal technology translate into

  • Consistent performance
  • Low non-uniformity
  • Low Defect Density
  • Full Utilization
  • High Product Yield
 

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