High-density Plasma Chemical Vapor Deposition Research Articles

Properties and Gap-Fill Capability of HPD-CVD Phosphosilicate Glass Films for Subquarter-Micrometer ULSI Device Technology

Properties of phosphosilicate glass films deposited at high‐density plasma (HDP) conditions have been studied for film application as a premetal dielectric in subquarter‐micrometer ultralarge scale integration (ULSI) device technology. Films were more dense and more stable compared to borophosphosilicate glass films, and provided void‐free gap‐fill for rectangular in section device structures with gap spacing and aspect ratio . Results of gap‐fill capability study and previously published data have been described with empirical linear dependence where k was found to be a function of HDP chemical vapor deposition (HDP‐CVD) conditions. It has been shown that to achieve void‐free gap‐fill capability of films for structures with gaps as low as and aspect ratios about four and higher, top comer rounding of structures and sidewall slope less than 90° must be implemented. An approach to evaluate an impact of structure rounding in HDP‐CVD gap‐fill capability has been proposed. ©2000 The Electrochemical Society

Stress Behavior of High Density Plasma Chemical Vapor Deposition Oxide Deposited on a Metal-Patterned Wafer

A high density plasma chemical vapor deposition (HDPCVD) oxide was used as an inter metal dielectric (IMD) due to its good gap-fill properties for compensating the tensile stress of Al metal layers. When the HDPCVD oxide was deposited on a metal patterned wafer, however, the oxide showed tensile stress. In order to understand the mechanism of the characteristic stress behavior of the HDPCVD oxide on a metal patterned wafer, the change in magnitude of the wafer bow was measured as a function of oxide thickness, and was modeled quantitatively using the density of metal patterns and the stress change of the metal film. In the model, the oxide deposited between metal lines was assumed to have tensile stress due to the relatively high shrinkage of the neighboring metal pattern. When the deposited HDPCVD oxide thickness was thinner than that of the metal film, only the stress of the lower parts of the metal film, which was connected to the oxide, could affect the change of the wafer bow value. When the deposited oxide thickness was greater than that of the metal film, the stress of the oxide above the metal film was assumed to be compressive. Using the above assumptions and a simple mathematical model, the change in magnitude of the wafer bow was calculated and compared with experimental results. The calculated data were in good agreement with the experimental values.

Method for angular sputter yield extraction for high-density plasma chemical vapor deposition simulators

High-density plasma chemical vapor deposition (HDP CVD) is a deposition method of current interest for gap fill of intermetal and interlevel dielectrics in semiconductor circuits. In HDP CVD processes the silicon dioxide film is often sputter etched as it is being deposited. The resputtering of the deposited film is a crucial process component in determining the final surface topography. Hence, it is imperative that the process simulators take this effect into consideration. In this work, we propose a method to extract the angle-dependent sputter yield for the HDP CVD process. This method constitutes the usage of our test structure. The extracted angular yield distribution is, then, used to simulate the final silicon dioxide profile. The distribution validity is determined by comparison of the simulated profile against the experimental profile. SPEEDIE (Stanford profile emulator for etching and deposition in integrated circuit engineering), a deposition and etching simulation program, was used as the simulator while experiments were performed on a HDP CVD system. A reasonably, good agreement was obtained between simulated and experimental profiles, indicating an accurate angular yield extraction. The extracted angular yield curve was compared with other such curves from literature for different ion energies. This comparison showed a trend of increase in the angle at which maximum yield occurs as the ion energy increased.