Methods for forming ruthenium films with beta-diketone containing ruthenium complexes and method for manufacturing metal-insulator-metal capacitor using the same

Abstract

Provided are 1) a method for forming a ruthenium film under a single process condition, whereby high adhesion of the ruthenium film to a lower layer is maintained, and 2) a method for manufacturing an metal-insulator-metal (MIM) capacitor using the ruthenium film forming method. The method for forming a ruthenium film includes supplying bis(isoheptane-2,4-dionato)norbornadiene ruthenium at a flow rate of 0.2-1 ccm and oxygen at a flow rate of 20-60 sccm, and depositing the ruthenium film at a temperature of 330-430° C. under a pressure of 0.5-5 Torr using chemical vapor deposition (CVD).

Description

[0001] This application is a divisional of U.S. application Ser. No. 10 / 657,596, filed Sep. 8, 2003 which claims priority to Korean Patent Application No. 2003-12044, filed on Feb. 26, 2003, in the Korean Intellectual Property Office, the disclosures of which are incorporated herein by reference in their entireties.BACKGROUND OF THE INVENTION [0002] 1. Field of the Invention [0003] The present invention relates to film formation in the manufacturing of metal-insulator-metal (MIM) capacitors. [0004] 2. Description of the Related Art [0005] Recently, due to their excellent electrical properties (such as resistivity), ruthenium and ruthenium compounds are being used as thin film electrode materials in the production of semiconductor devices for Dynamic Random Access Memory (DRAM) and Ferroelectric Random Access Memory (FeRAM). [0006] Ruthenium or ruthenium compound films are usually formed by sputtering or chemical vapor deposition (CVD) methods. In particular, CVD is preferred since t...

AI Technical Summary

Benefits of technology

The present invention provides a method for forming a ruthenium film using a single process condition that maintains high adhesion to a lower layer. This method involves supplying a two β-diketones-coordinated ruthenium complex and oxygen onto a substrate and depositing the ruthenium film using chemical vapor deposition (CVD). The ruthenium source can be a two β-diketones-coordinated ruthenium complex or a two β-diketones and one diene-coordinated ruthenium complex. The ruthenium film can be used for manufacturing a metal-insulator-metal (MIM) capacitor by sequentially depositing a first ruthenium film for a lower electrode, a dielectric layer, and a second ruthenium film for an upper electrode. The method provides a simple and effective way to form a ruthenium film with good adhesion and high quality.

Problems solved by technology

However, the bis(ethylcyclopentadienyl)ruthenium has problems in its use as a material for ruthenium films.

The main problem is that it is difficult to carry out the nucleation of the bis(ethylcyclopentadienyl)ruthenium.

However, if the oxygen flow rate and the deposition pressure are increased, the nucleation rate per unit area is excessively increased.

Formation of such needle-shaped ruthenium films results in surface morphology, increase of a sheet resistance, and generation of a leakage current.

On the other hand, if ruthenium films are formed under decreased deposition pressure and oxygen flow rate, the nucleation rate is excessively lowered.

In this case, however, due to the different process conditions used, the process burden is increased.

In addition, if the two steps are carried out in-situ, the process conditions become unstable during the transitional stage between the two steps.

As a result, the reproducibility and reliability of the process are lowered.

In addition, when a gas for cooling the wafer is introduced into a chamber, the wafer is often displaced due to the change in pressure.

As a result, the ruthenium films on the wafer do not have uniform thickness.

Meanwhile, the bis(ethylcyclopentadienyl)ruthenium has another problem in that ruthenium films made of bis(ethylcyclopentadienyl)ruthenium have relatively low adhesion to silicon dioxide films which are commonly used as interlayer insulating layers.

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