Taiwan Semiconductor Manufacturing Comp. Ltd.

Jui Fu Hsieh

Chih-Teng Liao

Yi-Jen Chen

Yu-Li Lin

Tzu-Chan Weng

Chia-Chi Yu

Chih-Shan Chen

Chih Hsuan Cheng

Chun-Lung Ni

Chia-Cheng Tai

Yan-Ting Shen

Shu Wen Wang

Dave Lo

Keng-Wei Lin

A two-step etch technique is used in a continuous polysilicon on oxide definition edge (CPODE) recess process to form a recess in which the CPODE structure is to be formed. The two-step process includes performing a first etch operation using an isotropic etch technique, in which a recess in a dummy gate structure is formed to a first depth. A second etch operation is performed using anisotropic etch technique to form the recess to a second depth. The use of the anisotropic etch technique results in a highly directional (e.g., vertical) etch of the dummy gate structure in the second etch operation. The highly directional etch provided by the anisotropic etch technique at or near the bottom of the dummy gate structure reduces, minimizes, and/or prevents etching into adjacent portions of an interlayer dielectric (ILD) layer and/or into source/drain region(s) under the portions of the ILD layer.

Semiconductor device and methods of formation

In a method, a first dielectric layer is formed over semiconductor fins, a second dielectric layer is formed over the first dielectric layer, the second dielectric layer is recessed below a top of each of the semiconductor fins, a third dielectric layer is formed over the recessed second dielectric layer, and the third dielectric layer is recessed below the top of the semiconductor fin, thereby forming a wall fin. The wall fin includes the recessed third dielectric layer and the recessed second dielectric layer disposed over the recessed third dielectric layer. The first dielectric layer is recessed below a top of the wall fin, a fin liner layer is formed, the fin liner layer is recessed and the semiconductor fins are recessed, and source/drain epitaxial layers are formed over the recessed semiconductor fins, respectively. The source/drain epitaxial layers are separated by the wall fin from each other.

Method of manufacturing a semiconductor device and a semiconductor device

A dummy gate structure may be formed for a semiconductor device. The dummy gate structure may be formed from an amorphous polysilicon layer. The amorphous polysilicon layer may be deposited in a blanket deposition operation. An annealing operation is performed for the semiconductor device to remove voids, seams, and/or other defects from the amorphous polysilicon layer. The annealing operation may cause the amorphous polysilicon layer to crystallize, thereby resulting in the amorphous polysilicon layer transitioning into a crystallized polysilicon layer. A dual radio frequency (RF) source etch technique may be performed to increase the directionality of ions and radicals in a plasma that is used to etch the crystallized polysilicon layer to form the dummy gate structure. The increased directionality of the ions increases the effectiveness of the ions in etching through the different crystal grain boundaries which increases the etch rate uniformity across the crystallized polysilicon layer.

Forming a dummy gate structure

A method includes determining a target etching depth for etching a plurality of dielectric regions in a wafer. The wafer includes a plurality of protruding semiconductor fins and the plurality of dielectric regions between the plurality of protruding semiconductor fins. The method further includes etching the plurality of dielectric regions, projecting a light beam on the wafer, and generating a spectrum from a reflected light reflected from the wafer, determining an end point for etching based on the spectrum. The end point is an expected time point. The plurality of dielectric regions are etched to the target etching depth. The etching of the plurality of dielectric regions is stopped at the end point.

End point control in etching processes

A method of forming a semiconductor device includes: forming a fin protruding above a substrate; forming a gate layer over the fin; and patterning the gate layer in a plasma etching tool using a plasma etching process to form a gate over the fin, where patterning the gate layer includes: turning on and off a top radio frequency (RF) source of the plasma etching tool alternately during the plasma etching process; and turning on and off a bottom RF source of the plasma etching tool alternately during the plasma etching process, where there is a timing offset between first time instants when the top RF source is turned on and respective second time instants when the bottom RF source is turned on.

Fin field-effect transistor device and method of forming

In a method of manufacturing a semiconductor device including a Fin FET, a fin structure extending in a first direction is formed over a substrate. An isolation insulating layer is formed over the substrate so that an upper portion of the fin structure is exposed from the isolation insulating layer. A gate structure extending in a second direction crossing the first direction is formed over a part of the fin structure. A fin mask layer is formed on sidewalls of a source/drain region of the fin structure. The source/drain region of the fin structure is recessed by a plasma etching process. An epitaxial source/drain structure is formed over the recessed fin structure. In the recessing the source/drain region of the fin structure, the plasma process comprises applying pulsed bias voltage and RF voltage with pulsed power.

A method includes forming a first portion of a spacer layer over a first fin and a second portion of the spacer layer over a second fin, performing a first etching process to recess the first portion of the spacer layer with respect to the second portion of the spacer layer to form first spacers on sidewalls of the first fin, subsequently performing a second etching process to recess the second portion of the spacer layer with respect to the first spacers to form second spacers on sidewalls of the second fin, where the second spacers are formed to a height greater than that of the first spacers, and forming a first epitaxial source/drain feature and a second epitaxial source/drain feature between the first spacers and the second spacers, respectively, where the first epitaxial source/drain feature is larger than that of the second epitaxial source/drain feature.

Forming source and drain features in semiconductor devices

In a method of manufacturing a semiconductor device including a Fin FET, a fin structure extending in a first direction is formed over a substrate. An isolation insulating layer is formed over the substrate so that an upper portion of the fin structure is exposed from the isolation insulating layer. A gate structure extending in a second direction crossing the first direction is formed over a part of the fin structure. A fin mask layer is formed on sidewalls of a source/drain region of the fin structure. The source/drain region of the fin structure is recessed by a plasma etching process. An epitaxial source/drain structure is formed over the recessed fin structure. In the recessing the source/drain region of the fin structure, the plasma etching process comprises applying pulsed bias voltage and RF voltage with pulsed power.

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Zhubei, Taiwan

Jui Fu Hsieh