By Cameron Chai
Tegal declared that it is currently in discussions to sell the fourth lot of its nano layer deposition patent portfolio pertaining to semiconductor processes.
The remaining portfolio covers thin film process technologies and structures pertaining to low-k dielectric and copper barrier technologies. Tegal had sold its nano layer deposition patent portfolio’s lots 1-3, comprising more than 30 patents, to several bidders for a total amount of roughly $4 million on December 30, 2011. Capital equipment manufacturers showed interest in these patents, whereas intellectual property (IP) aggregators and IC device manufacturers are showing interest in the fourth lot.
Integrated processes will be an essential stage of any integrated processing method for sophisticated low-k dielectrics that use porous low-k films. Moreover, Tegal’s patent portfolio comprises solutions for adhesion layers and composite barrier layers for copper metallization strategies, which have turned out to be more significant for chemical vapor deposition, nano layer deposition, atomic layer deposition of multiple layers such as barrier layers, adhesion layers, and seed layers of Mo, Ru or Cu.
Substitutes to existing physical vapor deposition methods with atomic layer deposition methods and their derivatives are being explored to fulfill the requirements for improved step coverage, higher aspect ratios, and control of Cu diffusion. These necessities in turn increase demands on the accurate control of sophisticated metallization schemes, especially at the lower metallization layers on sophisticated CMOS devices.
To break the step coverage restrictions of physical vapor deposition methods, developers are depending on nano layer deposition and atomic layer deposition techniques for building the seed, adhesion and barrier layers with atomic layer accuracy and control of stoichiometry, uniformity, and thickness. Through Tegal’s patents, IP aggregators and IC developers can strengthen their patent portfolio for sophisticated metallization schemes, especially ideal for the transformation from physical vapor deposition to atomic layer deposition and other layer-by-layer methods.