Process modules for transport polymerization of low epsilon thin films

Abstract

A Process Module (“PM”) is designed to facilitate Transport Polymerization (“TP”) of precursors that are useful for preparations of low Dielectric Constant (“∈”) films. The PM consists primarily of a Material Delivery System (“MDS”) with a high temperature Vapor Phase Controller (“VFC”), a TP Reactor, a Treatment Chamber, a Deposition Chamber and a Pumping System. The PM is designed to facilitate TP for new precursors and for film deposition and stabilization processes.

Description

BACKGROUND This invention is related to a polymer deposition system that is useful for the fabrication of an integrated circuit (“IC”). In particular, this invention is related to Process Module (“PM”) used for deposition of low dielectric (“∈”) thin films. Furthermore, this invention discloses chemistries of precursor and methods for utilization of the PM to convert the precursor into dielectric thin film. During the construction of ICs with shrinking device geometries, an increase in capacitance, mainly on the same layer of interconnects can result in unacceptable cross talk and resistance-capacitance (“RC”) delay. This RC delay has become a serious problem for ICs with feature size of less than 0.18 μm. Thus, the dielectric constant of the current insulation materials from which IC's are constructed must be decreased to meet the needs for fabrication of future ICs. In addition to dielectric and conducting layers, the “barrier layer” may include metals such as Ti, Ta, W, and Co ...

AI Technical Summary

Problems solved by technology

During the construction of ICs with shrinking device geometries, an increase in capacitance, mainly on the same layer of interconnects can result in unacceptable cross talk and resistance-capacitance (“RC”) delay.

This RC delay has become a serious problem for ICs with feature size of less than 0.18 μm.

These current dielectric materials used in the manufacturing of the ICs have already proven to be inadequate in several ways for their continued use in mass production of the future IC's.

The present lack of qualified low dielectric materials now threatens to derail the continued shrinkage of future IC's.

However, the decomposition temperature (“Td”) of PPX was too low, and the dielectric constant of the resulting polymer (∈=3.2 to 2.7) was not low enough (Selbrede and Zucker, Proc.

DUMIC Conference, 125-128 (1997) reported that annealing a deposited layer of PPX increases the thermal stability, but even then, the subsequent loss of polymer was too great to be useful for future IC manufacturing.

These metal ions result in metallic contamination of deposited thin films.

Further, the wafer is protected by a heat shield, which must be kept close to the heat source, and thus, is not ideally suited to act as a diffusion plate to ensure the even distribution of intermediates onto the wafer surface.

Thus, deposition of precursors onto the wafer surface is not easily regulated and the thickness of dielectric films cannot be made constant over the entire wafer surface.

In addition, the current deposition system provides means to control the feed rate of precursor and substrate temperature, thus the resultant film properties are not available from using any of the existing deposition systems.

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