Research On Characteristic Of MOCVD Barrier TiN Film

The continuous improvement of transistor speed depends on the device miniaturization. However, the time delay from parasitic capacitance and resistance retard speed up. In order to reduce time delay in circuit, CONTACT and VIA fabrication process has transformed. As a low resistivity, high thermal and chemical stability material, TiN film is widely used in CONTACT and VIA process. The thin film deposited by Physical Vapor Deposition can not meet the step coverage of high aspect ratio in 0.18μm~90nm size process, otherwise CVD has been one of the most focused field by people for its better step coverage and low temperature deposition.In this paper we will discuss the TiN thin film formed by MOCVD system, introduce the MOCVD process, chamber mechanism and film characteristic evaluation method. Also the rule of TiN film deposition was shown by comparing related process parameters and TiN film characteristic on step coverage, film uniformity, particle contamination, impurity concentration and electrical characteristic was given based on experiments.From the result, we can conclude that at AR 6:1 condition, bottom step coverage can reach at lease 70%, Carbon element concentration can be reduced to 3.6atoms% after plasma treatment, also better thickness uniformity and lower resistivity was achieved after optimization.