At&t Bell Laboratories

Lucent Technologies Inc.

American Telephone & Telegraph Co., At&t Bell Laboratories

Pang-Dow Foo

Chien-Shing Pai

Man Fei Yan

William T Lynch

Ronald J Schutz

Leonard Jay Olmer

Ajit S Manocha

Robert E Dean

Earl Ryan Lory

Tai-Chan D Huo

Frank B Alexander, Jr

John F Miner

The use of a deposition process involving a plasma struck in a gas including tetraethoxysilane and a source of oxygen yields, at low temperatures, conformal coatings of silicon dioxide. This process has significant implications for semiconductor device fabrication involving the deposition of a dielectric over a metallic non-planar structure.

Low temperature deposition of silicon oxides for device fabrication

Integrated circuits employing titanium nitride are significantly improved by using a specific method for formation of the titanium nitride in the device fabrication. In particular, a plasma such as one formed in an electron cyclotron resonance apparatus is employed to dissociate a source of nitrogen and a source of hydrogen and the dissociation products are combined at the integrated circuit deposition substrate with titanium tetrachloride. The resulting deposition is essentially devoid of chlorine and has advantageous step-coverage properties.

Process for fabricating integrating circuits

A method of forming silicon dioxide layers by bias ECR is described. The layers are formed by reacting oxygen with TEOS or TMCTS. High-quality, void-free layerc can be formed over conductor patterns having high-aspect-ratio intermetallic spacings.

Method of forming oxide layers by bias ECR plasma deposition

Disclosed is a method for forming a silicon dioxide layer on a substrate by radio-frequency deposition from a plasma comprising oxygen, argon, and tetraethyl orthosilicate (TEOS) or tetramethyl cyclotetrasiloxane (TMCTS). A negative bias is imparted to the substrate. The resulting ion bombardment induces surface migration. Because TEOS and TMCTS have a relatively high mean free path for surface migration, the filling of soft spots and key holes is promoted.

Method for depositing dielectric layers

In the fabrication of electrodes for transistors in the BiCMOS integrated circuit, vertical windows etched in a relatively thick TEOS (or other suitable dielectric) layer, located on a relatively thin polysilicon layer, in turn located on relatively tin oxide layer areas and on relatively thick oxide layer areas, are used to define areas where polysilicon electrode material is to remain. Polysilicon is deposited in the windows in the relatively thick insulating layer, to form the basis for the desired electrode in each window. The relatively thin polysilicon layer (or, alternatively an .alpha.-amorphous silicon layer) is thereafter used as an etch stop during the subsequent removal of the relatively thick dielectric layer. Thereafter both MOS and bipolar transistors can be fabricated using the windows to define the extents of the gate regions of the MOS transistors and the extents of the emitter regions of the bipolar transistors. In addition, both the source and drain electrodes of the MOS transistors and the base electrodes of the bipolar transistors can then be simultaneously formed in a self-aligned manner without the need for etching into the underlying semiconductor substrate in which the integrated circuit is being formed.

Formation of integrated circuit electrodes

By adjusting the AC field conditions, i.e., by grounding the environment of a substrate being etched with a chlorine-containing plasma, a significant increase in etch selectivity is achieved. By applying a similar AC field adjustment to the reaction chamber surfaces, excellent etch uniformity is achieved in conjunction with excellent selectivity.

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Berkeley Heights, NJ, United States of America

Pang-Dow Foo