An Overview of High Melting Point Metallization

Abstract

This paper reviews the applications of the high-melting point metallization both for the conventional devices and integrated circuits at considerably higher temperatures. Conventional devices generally operate between room temperature and ∼100 °C, depending on the nature and density of devices and cooling effectiveness of the packaging. In such cases the need for the high melting point metal arises due to (a) increasing current density, leading to enhanced electromigration, and (b) ease of post-metallization processing. On the other hand there are high power devices and devices that operate in environment of high temperatures. In this latter use there are additional needs of a high melting point metallization scheme. Such metallization should also be immune to thermally induced metallurgical/chemical reactions and internal changes in the metallization properties such as electrical resistivity, microstructure, stress, etc. In this paper we will examine these requirements for both applications and then review metals, alloys, or sandwich metallization schemes that may be able to satisfy our needs of future.

Indexing terms:

• High melting point metallization
• Thin film microstructure