Sgs-Thomson Microelectronics Limited

Stmicroelectronics Gmbh

Yih-Shung Lin

Fu-Tai Liou

Fusen E Chen

Che-Chia Wei

Girish A Dixit

Alex Kalnitsky

Lun-Tseng Lu

Loi Ngoc Nguyen

Timothy E Turner

John L Walters

De-Dui Liao

De-Dul Liao

Kuei-Wu Huang

A method for fabricating interlevel contacts in semiconductor integrated circuits provides for formation of a contact opening through an insulating layer. A layer of refractory metal, or refractory metal alloy, is deposited over the surface of the integrated circuit chip. An aluminum layer is then deposited at a significantly elevated temperature, so that an aluminum/refractory metal alloy is formed at the interface between the aluminum layer and the refractory metal layer. Formation of such an alloy causes an expansion of the metal within the contact opening, thereby filling the contact opening and providing a smooth upper contour to the deposited aluminum layer.

Method for fabricating interlevel contacts of aluminum/refractory metal alloys

A method for forming an aluminum contact through an insulating layer includes the formation of an opening. A barrier layer is formed, if necessary, over the insulating layer and in the opening. A thin refractory metal layer is then formed over the barrier layer, and aluminum deposited over the refractory metal layer. Proper selection of the refractory metal layer and aluminum deposition conditions allows the aluminum to flow into the contact and completely fill it. Preferably, the aluminum is deposited over the refractory metal layer without breaking vacuum.

Aluminum contact structure for integrated circuits

Methods of forming, in an integrated circuit, aluminum-silicon contacts with a barrier layer is disclosed. The barrier layer is enhanced by the provision of titanium oxynitride layers adjacent the silicide film formed at the exposed silicon at the bottom of the contact. The titanium oxynitride may be formed by depositing a low density titanium nitride film over a titanium metal layer that is in contact with the silicon in the contact; subsequent exposure to air allows a relatively large amount of oxygen and nitrogen to enter the titanium nitride. A rapid thermal anneal (RTA) both causes silicidation at the contact location and also results in the oxygen and nitrogen being gettered to what was previously the titanium/titanium nitride interface, where the oxygen and nitrogen react with the titanium metal and nitrogen in the, atmosphere to form titanium oxynitride. The low density titanium nitride also densifies during the RTA. Alternative embodiments are also disclosed in which the silicide is formed first, prior to the formation of additional titanium oxynitride by air exposure and RTA, or by sputter deposition. Each of these processes produces a high-quality barrier contact structure overlying a silicide film, where the barrier structure includes titanium oxynitride and titanium nitride.

Integrated circuit with improved contact barrier

Interlevel contacts in semiconductor integrated circuits are fabricated by formation of a contact opening through an insulating layer. A layer of refractory metal, or refractory metal alloy, is deposited over the surface of the integrated circuit chip. An aluminum layer is then deposited at a significantly elevated temperature, so that an aluminum/refractory metal alloy is formed at the interface between the aluminum layer and the refractory metal layer. Formation of such an alloy causes an expansion of the metal within the contact opening, thereby filling the contact opening and providing a smooth upper contour to the deposited aluminum layer.

Interlevel contact including aluminum-refractory metal alloy formed during aluminum deposition at an elevated temperature

Methods of forming, in an integrated circuit, aluminum-silicon contacts with a barrier layer is disclosed. The barrier layer is enhanced by the provision of titanium oxynitride layers adjacent the silicide film formed at the exposed silicon at the bottom of the contact. The titanium oxynitride may be formed by depositing a low density titanium nitride film over a titanium metal layer that is in contact with the silicon in the contact; subsequent exposure to air allows a relatively large amount of oxygen and nitrogen to enter the titanium nitride. A rapid thermal anneal (RTA) both causes silicidation at the contact location and also results in the oxygen and nitrogen being gettered to what was previously the titanium/titanium nitride interface, where the oxygen and nitrogen react with the titanium metal and nitrogen in the atmosphere to form titanium oxynitride. The low density titanium nitride also densifies during the RTA. Alternative embodiments are also disclosed in which the silicide is formed first, prior to the formation of additional titanium oxynitride by air exposure and RTA, or by sputter deposition. Each of these processes produces a high-quality barrier contact structure overlying a silicide film, where the barrier structure includes titanium oxynitride and titanium nitride.

Method of fabricating an integrated circuit with improved contact barrier

A method for planarizing integrated circuit topographies, wherein, after a first layer of spin-on glass is deposited, a layer of low-temperature oxide is deposited before a second layer of spin-on glass.

Enhanced planarization technique for an integrated circuit

Method for forming an aluminum contact

A method is provided for depositing aluminum thin film layers to form contacts in a semiconductor integrated circuit device. All or some of the deposition process occurs at relatively low deposition rates at a temperature which allows improved surface migration of the deposited aluminum atoms. Aluminum deposited under these conditions tends to fill contact vias without the formation of voids. The low temperature deposition step can be initiated by depositing aluminum while a wafer containing the integrated circuit device is being heated from cooler temperatures within the deposition chamber.

Method for forming a metal contact

A method is provided for forming contact via in an integrated circuit. Initially, a first buffer layer is formed over an insulating layer in an integrated circuit. The first buffer layer has a different etch rate from the insulating layer. A second buffer layer is then formed over the first buffer layer, with the second buffer layer having an etch rate which is faster than the first buffer layer. An isotropic etch is performed to create an opening through the second buffer layer and a portion of the first buffer layer. Because the second buffer layer etches faster than the first buffer layer, the slant of the sideswalls of the opening can be controlled. An anisotropic etch is then performed to complete formation of the contact via.

Semiconductor contact via structure

Method for forming an aluminum contact through an insulating layer

Integrated circuit with a titanium nitride contact barrier having oxygen

Integrated circuit with enhanced planarization

A method for forming a contact via in an integrated circuit includes the formation of an aluminum conductive element on an integrated circuit device. A conformal insulating layer is then deposited over the device. Using a masking layer, an anisotropic etch is performed to open a via through the conformal insulating layer. During the anisotropic etch, polymers are created from the resist and etch chemistry and adhere to the sidewalls of the via. A resist developer containing Tetra Methyl Amonium Hydroxide is used to remove the polymers from the via. A contact may now be formed by depositing conductive material into the via.

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Carrollton, TX, United States of America

Yih-Shung Lin