Tokyo Electron Limited

Eric Chih-Fang Liu

Akiteru Ko

Angelique Denise Raley

David L O'Meara

Katie Lutker-Lee

Henan Zhang

Shihsheng Chang

Nihar Mohanty

Shan Hu

Xinghua Sun

Sangita Kumari

Peter Delia

Andrew W Metz

Kai-Hung Yu

Subhadeep Kal

Yun Han

Yen-Tien Lu

Ya-Ming Chen

Steven Grzeskowiak

Anton J deVillers

Hiroaki Niimi

Robert Daniel Clark

Gerrit J Leusink

Anthony Dip

Cory Wajda

Richard Farrell

Soo Doo Chae

Jodi Grzeskowiak

Toshiharu Wada

Gyanaranjan Pattanaik

Elliott Franke

Ying Trickett

Stephanie Oyola-Reynoso

Angélique D Raley

Daniel Santos Rivera

Embodiments of improved process flows and methods are provided in the present disclosure to form air gaps between metal interconnects. More specifically, the present disclosure provides improved process flows and methods that utilize a wet etch process to form recesses between metal interconnects formed on a patterned substrate. Unlike conventional air gap integration methods, the improved process flows and methods described herein utilize the critical dimension (CD) dependent etching provided by wet etch processes to etch an intermetal dielectric material formed between the metal interconnects at a faster rate than the intermetal dielectric material is etched in surrounding areas of the patterned substrate. This enables the improved process flows and methods described herein to form recesses (and subsequently form air gaps) between the metal interconnects without using a dry etch process.

Wet etch process and methods to form air gaps between metal interconnects

A method of processing a substrate that includes: forming recesses in a first mask layer over a mask stack including a lower hardmask, a middle mask, and an upper hardmask, the recesses defining an initial pattern including a plurality of spacer structures, each of the spacer structures having a first sidewall and an opposite second sidewall, the first sidewall having a different height from the second sidewall; etching the upper hardmask, selectively to the middle mask, to transfer the initial pattern to the upper hardmask; etching the middle mask, selectively to the lower hardmask and the patterned upper hardmask, to transfer a pattern of the patterned upper hardmask to the middle mask; and etching the lower hardmask, selectively to the patterned middle mask, to transfer a pattern of the patterned middle mask to the lower hardmask.

Double hardmasks for self-aligned multi-patterning processes

A method of forming a semiconductor device includes forming, over a hardmask layer and an underlying layer of a substrate, a pattern of first trenches between adjacent template lines, each of the first trenches exposing a portion of the hardmask layer, and each of the template lines including a mandrel and spacers on sidewalls of the mandrel; forming a pattern of first blocks over the pattern of the first trenches and the template lines, the first blocks dividing the first trenches to form a pattern of first stencil trenches; transferring the pattern of first stencil trenches to the hardmask layer to form a pattern of first hardmask trenches, each of the first hardmask trenches exposing a portion of the underlying layer; forming a first fill layer filling the first hardmask trenches and exposing the mandrels; selectively removing the mandrels to form second trenches, each of the second trenches exposing a portion of the hardmask layer; and forming a conformal liner in the second trenches and over a surface of the spacers, a surface of the first blocks, and a surface of the first fill layer to form third trenches.

Double patterning method of patterning a substrate

A method of fabricating an amorphous carbon layer (ACL) mask includes forming an ACL on an underlying layer. The ACL includes a soft ACL portion that has a first hardness and a hard ACL portion that has a second hardness. The soft ACL portion underlies the hard ACL portion. The second hardness is greater than the first hardness. The method further includes forming a patterned layer over the ACL and forming an ACL mask by etching through both the soft ACL portion and the hard ACL portion of the ACL to expose the underlying layer using the patterned layer as an etch mask. Forming the ACL may include depositing one or both of the soft ACL portion and the hard ACL portion. Processing conditions may also be varied while forming the ACL to create a hardness gradient that transitions from softer to harder.

Variable hardness amorphous carbon mask

An additional non-photoresist layer may be formed on patterned photoresist layers. The additional layer may be preferentially formed on the tops of the photoresist layer versus the sidewalls of the photoresist layer. In addition, the additional layer may be preferential formed on the tops of the photoresist layer versus exposed surfaces of layers underlying the photoresist layer. In this manner, the patterned structures formed by the photoresist layer are less likely to have line opens due to photoresist height variability or the relative thinness of the photoresist height used. Further, the formation of the additional layer may be through a cyclic deposition/trim process. The trim step of the cyclic process may also serve as a descum step that helps reduce line bridging and scumming. In one embodiment, the additional non-photoresist layer may be an organic polymer layer.

Method for reducing lithography defects and pattern transfer

A method for filling recessed features with a low-resistivity metal. The method includes providing a patterned substrate containing a recessed feature formed in a first layer and a second layer that is exposed in the recessed feature, forming a nucleation enhancement layer on a sidewall of the first layer in the recessed feature and depositing a metal layer in the recessed feature by vapor phase deposition, where the metal layer is deposited on the second layer and on the nucleation enhancement layer. An initial metal layer may be selectively formed on the second layer in the recessed feature before forming the nucleation enhancement layer.

Method for filling recessed features in semiconductor devices with a low-resistivity metal

Embodiments of improved process flows and methods are provided in the present disclosure to control fin height and channel area in a fin field effect transistor (FinFET) having gaps of variable CD. More specifically, the present disclosure provides improved transistor fabrication processes and methods that utilize a wet etch process, instead of a dry etch process, to remove the oxide material deposited within the gaps formed between the fins of a FinFET. By utilizing a wet etch process, the improved transistor fabrication processes and methods described herein provide a means to adjust or individually control the fin height of one or more the fins, thereby providing greater control over the channel area of the FinFET.

Wet etch process and method to control fin height and channel area in a fin field effect transistor (FinFET)

The present disclosure combines chemical mechanical polishing (CMP), wet etch and deposition processes to provide improved processes and methods for planarizing an uneven surface of a material layer deposited over a plurality of structures formed on a substrate. A CMP process is initially used to smooth the uneven surface and provide complete local planarization of the material layer above the plurality of structures. After achieving complete local planarization, a wet etch process is used to etch the material layer until a uniform recess is formed between the plurality of structures and the material layer is provided with a uniform thickness across the substrate. In some embodiments, an additional material layer may be deposited and a second CMP process may be used to planarize the additional material layer to provide the substrate with a globally planarized surface.

Methods for planarizing a substrate using a combined wet etch and chemical mechanical polishing (CMP) process

Methods are provided herein for forming spacers on a patterned substrate. A self-aligned multiple patterning (SAMP) process is utilized for patterning structures, spacers formed adjacent mandrels, on a substrate. In one embodiment, a novel approach of etching titanium oxide (TiO) spacers is provided. Highly anisotropic etching of the spacer along with a selective top deposition is provided. In one embodiment, an inductively coupled plasma (ICP) etch tool is utilized. The etching process may be achieved as a one-step etching process. More particularly, a protective layer may be selectively formed on the top of the spacer to protect the mandrel as well as minimize the difference of the etching rates of the spacer top and the spacer bottom. In one embodiment, the techniques may be utilized to etch TiOspacers formed along amorphous silicon mandrels using an ICP etch tool utilizing a one-step etch process.

Method for highly anisotropic etching of titanium oxide spacer using selective top-deposition

A method is described for patterning a dielectric layer disposed over a semiconductor substrate layer. The patterning process includes forming a patterned hard mask layer over the dielectric layer, the patterned hard mask layer exposing a portion of a major surface of the dielectric layer. A portion of the dielectric layer is removed by a cyclic etch process, where performing one cycle of the cyclic etch process comprises forming a capping layer selectively over the patterned hard mask layer and performing a timed etch process that removes material from the dielectric layer. In another method, the deposition over the hard mask and the removal of the portion of the dielectric layer are performed concurrently.

Method for patterning a dielectric layer

Embodiments are described herein that apply capping layers to cores prior to spacer formation in self-aligned multiple patterning (SAMP) processes to achieve vertical spacer profiles. For one embodiment, a plasma process is used to deposit a capping layer on cores, and this capping layer causes resulting core profiles to have protective caps. These protective caps formed with the additional capping layer help to reduce or minimize material loss and corner loss of the core material during spacer deposition and spacer etch processes. This reduction in core material loss improves the resulting spacer profile so that a more vertical profile is achieved. For one embodiment, an angle of 80-90 degrees is achieved for vertical sidewalls of the spacers adjacent core sites with respect to the horizontal surface of the underlying layer, such as a hard mask layer formed on a substrate for a microelectronic workpiece.

Method and system for capping of cores for self-aligned multiple patterning

Methods process microelectronic workpieces with inverse extreme ultraviolet (EUV) patterning processes. In part, the inverse patterning techniques are applied to reduce or eliminate defects experienced with conventional EUV patterning processes. The inverse patterning techniques include additional process steps as compared to the conventional EUV patterning processes, such as an overcoat process, an etch back or planarization process, and a pattern removal process. In addition, further example embodiments combine inverse patterning techniques with line smoothing treatments to reduce pattern roughness and achieve a target level of line roughness. By using this additional technique, line pattern roughness can be significantly improved in addition to reducing or eliminating microbridge and/or other defects.

Methods for EUV inverse patterning in processing of microelectronic workpieces

In certain embodiments, a method of forming a semiconductor device includes forming a patterned resist layer over a hard mask layer using an extreme ultraviolet (EUV) lithography process. The hard mask layer is disposed over a substrate. The method includes patterning the hard mask layer using the patterned resist layer as an etch mask. The method includes smoothing the hard mask layer by forming, using a first atomic layer etch step, a first layer by converting a first portion of the hard mask layer, and by removing, using a second atomic layer etch step, the first layer.

Forming a semiconductor feature using atomic layer etch

A method of forming a device includes depositing a first etch mask layer over a mandrel formed using a lithography process. The method includes depositing a second etch mask layer over the first etch mask layer. The method includes, using a first anisotropic etching process, etching the first etch mask layer and the second etch mask layer to form an etch mask including the first etch mask layer and the second etch mask layer. The method includes removing the mandrel to expose an underlying surface of the layer to be patterned. The method includes, using the etch mask, forming a feature by performing a second anisotropic etching process to pattern the layer to be patterned, where during the first anisotropic etching process, the first etch mask layer etches at a first rate and the second etch mask layer etches at a second rate, and where the first rate is different from the second rate.

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Albany, NY, United States of America

Eric Chih-Fang Liu