Micron Technology Incorporated

Micro Technology, Inc.

John H Givens

Paul A Farrar

Brenda D Kraus

Russell C Zahorik

Mark E Jost

Richard L Elliott

Shane B Leiphart

Richard H Lane

Randle D Burton

E Allen McTeer

Guy F Hudson

A method for manufacturing an interconnect structure situated on a semiconductor wafer having a substrate assembly thereon. The interconnect structure is formed in a recess such as a trench, a hole, a via, or a combination of a trench and a hole or via within a dielectric material situated on the substrate assembly of the semiconductor wafer. At least one barrier layer is deposited within the recess. A seed layer helping to promote nucleation, deposition, and growth of a material that will be used to fill up the recess is then deposited on the barrier layer. An electrically conductive layer is then formed upon the seed layer. An energy absorbing layer will then be formed upon the conductor layer, where the energy absorbing layer has a greater thermal absorption capacity than that of the electrically conductive layer. The energy absorbing layer is heated, with or without an applied heightened pressure, to cause the conductor layer to flow so as to fill voids that have formed within the dielectric structure. Following the steps of heating or heating and pressurizing the energy absorbing layer, both the energy absorbing layer and a portion of the conductive layer situated above the dielectric structure are removed.

Utilization of energy absorbing layer to improve metal flow and fill in a novel interconnect structure

A recess having a height-to-width aspect ratio from about 6:1 to about 10:1 in a semiconductor structure is disclosed with a method of forming the same. In a first embodiment, a refractory metal layer is formed in the recess, which can be a trench, a contact hole, or a combination thereof. A refractory metal nitride layer is then formed on the refractory metal layer. A heat treatment is used to form a metal silicide contact at the bottom of the contact hole upon a semiconductor material. In a first alternative method, an ammonia high-temperature treatment is conducted to remove undesirable impurities within the refractory metal nitride layer lining the contact hole and to replace the impurities with more nitrogen. In a second alternative method, a second refractory metal nitride layer is formed by PVD upon the first refractory metal nitride layer. In either alternative, a metallization layer is deposited within the recess.

Semiconductor device with metal fill by treatment of mobility layers including forming a refractory metal nitride using TMEDT

A recess having a height-to-width aspect ratio from about 6:1 to about 10:1 in a semiconductor structure is taught with a method of forming the same. In a first embodiment, a refractory metal layer is formed in the recess, which can be a trench, a contact hole, or a combination thereof. A refractory metal nitride layer is then formed on the refractory metal layer. A heat treatment is used to form a metal silicide contact at the bottom of the contact hole upon a semiconductor material. In a first alternative method, an ammonia high-temperature treatment is conducted to remove undesirable impurities within the refractory metal nitride layer lining the contact hole and to replace the impurities with more nitrogen. In a second alternative method, a second refractory metal nitride layer is formed by PVD upon the first refractory metal nitride layer. In either alternative, a metallization layer is deposited within the recess. High pressure and temperature are used to substantially fill the recess with the metallization layer. Following the substantially filling of the recess, residual surface metallization may at least be partially removed by techniques such as etch back or CMP.

Method for metal fill by treatment of mobility layers

In one aspect, the invention includes a processing method, comprising: a) providing a substrate having a high aspect ratio opening therein; b) forming a metal-comprising layer over the opening; c) providing a first pressure against the metal-comprising layer; and d) ramping the pressure that is against the metal-comprising layer to a second pressure at a rate of from about 1 atmosphere per second about 100 atmospheres per second. In another aspect, the invention includes a processing method, comprising: a) providing a substrate having a high aspect ratio opening therein, the opening having a widest portion and a width at said widest portion; b) in a first chamber, sputter depositing a metal to form a metal-comprising layer over the opening, the metal-comprising layer having a thickness that is at least about twice the width of the opening; c) transferring the substrate to a second chamber having a first pressure therein; and d) while the substrate is within the second chamber, ramping the pressure within the second chamber at a rate of at least about 20 atmospheres per second to a second pressure.

Processing methods for providing metal-comprising materials within high aspect ratio openings

Semiconductor processing methods of forming integrated circuitry are described. Embodiments provide a substrate having circuit devices. At least three layers are formed over the substrate and through which electrical connection is to be made with at least two of the circuit devices. The three layers comprise first and second layers having an etch stop layer interposed therebetween. Contact openings are formed through the three layers and a patterned masking layer is formed over the three layers to define a conductive line pattern. Material of an uppermost of the first and second layers is selectively removed, relative to the etch stop layer, to define troughs joined with the contact openings. Conductive material is subsequently formed within the joined troughs and contact openings. In some embodiment, contact openings are formed that have an aspect ratio of no less than about 10:1.

Semiconductor processing methods of forming integrated circuitry

A method of forming structures in semiconductor devices through a buffer or insulator layer comprises the use of a silicon hard mask between a patterned resist layer for etching the structures and an underlying barrier layer. The silicon hard mask acts as a backup to the resist layer, preventing the potential etching of the barrier layer which is protected by the resist layer by acting as an etch stop if the first resist layer is ablated away during the etching of the openings for the structures. This allows for a thinner layer of resist material to be used. After etching, a layer of silicidable material is deposited over the silicon hard mask and the resulting structure is annealed to turn the silicon hard mask into a silicide material. The silicide material is removed by an abrasive method, such as by chemical mechanical planarization.

Utilization of disappearing silicon hard mask for fabrication of semiconductor structures

A thermal processing method is described which improves integrated circuit metal polishing and increases conductivity following polish. A method of fabricating a metal layer in an integrated circuit is described which comprises the steps of depositing a layer of metal alloy which contains alloy dopant precipitates, and performing a first anneal of the integrated circuit to drive the alloy dopants into solid solution. The metal is quenched to prevent the alloy dopants from coming out of solution prior to removing excess metal alloy with a polish process. To improve conductivity after polishing, the dopants are allowed to come out of solution. The metal alloy is described as aluminum with alloy dopants of silicon and copper where the first anneal is performed at 400 to 500&deg; C. This process is particularly applicable to fabrication of interconnects formed using a dual damascene process. The integrated circuit is described as any circuit, but can be a memory device such as a DRAM.

Thermal processing of metal alloys for an improved CMP process in integrated circuit fabrication

An interconnect structure, which can have three-levels, is formed by a metallization method in an electrical circuit. The method comprises providing a substrate assembly and depositing thereon a first dielectric layer thereover. A second dielectric layer is then deposited over the first dielectric layer. The second dielectric layer is patterned and anisotropically etched to form contact corridors. The second dielectric layer is again patterned and etched to form trenches, some of which are immediately above the contact corridors. An electrically conductive material is deposited to fill the contact corridors and trenches, and to leave a portion of the electrically conductive material above the second dielectric layer and directly above both the contact corridors and the trenches. The deposition forms a unitary three-level interconnect having a contiguous trench below a contact corridor below a metal line, where the metal line is above the second dielectric layer. An optional antireflective coating can be deposited to assist in filling the trenches and contact corridor. Finally, patterning and etching of the electrically conductive material above the second dielectric layer forms metal lines for the electrical circuit.

Three-level unitary interconnect structure

A method of forming structures in semiconductor devices through a buffer or insulator layer comprises the use of a silicon hard mask between a patterned resist layer for etching the structures and an underlying barrier layer. The silicon hard mask acts as a backup to the resist layer, preventing the potential etching of the barrier layer which is protected by the resist layer by acting as an etch stop if the first resist layer is ablated away during the etching of the openings for the structures. After etching, a layer of silicidable material is deposited over the silicon hard mask and the resulting structure is annealed to turn the silicon hard mask into a silicide material. The silicide material is removed by an abrasive method, such as by CMP.

Methods for utilization of disappearing silicon hard mask for fabrication of semiconductor structures

A void is defined between adjacent wiring lines to minimize RC coupling. The void has a low dielectric value approaching 1.0. For one approach, hollow silicon spheres define the void. The spheres are fabricated to a known inner diameter, wall thickness and outer diameter. The spheres are rigid enough to withstand the mechanical processes occurring during semiconductor fabrication. The spheres withstand elevated temperatures up to a prescribed temperature range. At or above a desired temperature, the sphere walls disintegrate leaving the void in place. For an alternative approach, adjacent wiring lines are &ldquo;T-topped&rdquo; (i.e., viewed cross-sectionally). Dielectric fill is deposited in the spacing between lines. As the dielectric material accumulates on the line and substrate walls, the T-tops grow toward each other. Eventually, the T-tops meet sealing off an internal void.

Reduced RC between adjacent substrate wiring lines

A method of forming structures in semiconductor devices through a buffer or insulator layer comprising the use of a silicon hard mask between a patterned resist layer for etching the structures and an underlying barrier layer. The silicon hard mask acts as a backup to the resist layer, preventing the potential etching of the barrier layer which is protected by the resist layer by acting as an etch stop if the first resist layer is ablated away during the etching of the openings for the structures. This allows for a thinner layer of resist material to be used. After etching, a layer of silicidable material is deposited over the silicon hard mask and the resulting structure is annealed to turn the silicon hard mask into a silicide material. The silicide material is removed by an abrasive method, such as by chemical mechanical planarization.

A recess having a height-to-width aspect ratio from about 6:1 to about 10:1 in a semiconductor structure is taught with a method of forming the same. In a first embodiment, a refractory metal layer is formed in the recess, which can be a trench, a contact hole, or a combination thereof. A refractory metal nitride layer is then formed on the refractory metal layer. A heat treatment, preferably RTP, is used to form a metal silicide contact at the bottom of the contact hole upon semiconductor material. In a first alternative method, an ammonia high-temperature treatment is conducted to remove undesirable impurities within the refractory metal nitride layer lining the contact hole and to replace the impurities with more nitrogen. In a second alternative method, a second refractory metal nitride layer is formed by PVD upon the first refractory metal nitride layer. In either alternative, metallization layer is deposited with the recess. High pressure and temperature are used to substantially fill the recess with the metallization layer. In a preferred embodiment, deposition of the first refractory metal nitride layer is accomplished using trimethylethylenediamine tris (dimethylamino) titanium (TMEDT). The aspect ratio of a recess that can be substantially filled can exceed 8:1 when using a TMEDT-deposited refractory metal nitride layer and a subsequent deposition of a second refractory metal nitride layer by PVD. Following the substantially filling of the recess, residual surface metallization may be at least partially removed by such techniques as etch back or CMP.

Method for improved metal fill by treatment of mobility layers

A method of forming structures in semiconductor devices through a buffer or insulator layer comprising the use of a silicon hard mask between a patterned resist layer for etching the structures and an underlying barrier layer. The silicon hard mask acts as a backup to the resist layer, preventing the potential etching of the barrier layer which is protected by the resist layer by acting as an etch stop if the first resist layer is ablated away during the etching of the openings for the structures. This allows for a thinner layer of resist material to be used because no additional resist is required to provide a &ldquo;margin of error&rdquo; during the etching to assure the integrity of the barrier layer. After etching, a layer of silicidable material is deposited over the silicon hard mask and the resulting structure is annealed to turn the silicon hard mask into a silicide material. The silicide material is removed by an abrasive method, such as by CMP. A silicon hard mask is difficult to remove by such an abrasive method. However, a silicide material is conducive to abrasive removal. The deposition and annealing of the silicidable material can be a part of the formation of a contact silicide layer at the bottom of a contact opening during the formation of a bitline contact or a capacitor contact.

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Meridian, ID, United States of America

John H Givens