Abstract: Methods are provided for fabricating a semiconductor device on and in a semiconductor substrate. In accordance with an exemplary embodiment of the invention, one method comprises forming a sacrificial mandrel overlying the substrate, the sacrificial mandrel having sidewalls. Sidewall spacers are formed adjacent the sidewalls of the sacrificial mandrel. The sacrificial mandrel is removed using an ashing process, and the substrate is etched using the sidewall spacers as an etch mask after removal of the sacrificial mandrel.

Abstract: To reduce the width of a MOSFET gate, the gate is formed with a hardmask formed thereupon. An isotropic etch is then performed to trim the gate in order to reduce the width of the gate. The resulting gate may be formed with a width that is narrower than a minimum width achievable solely through conventional projection lithography techniques.

Abstract: A method of forming a shallow trench isolation (STI) region in a silicon substrate creates an STI region that extends above a top surface of the silicon substrate. A planarizing dielectric layer is formed on the substrate and extends above the field oxide regions. The planarizing dielectric layer is removed by chemical mechanical polishing or blanket etch back, for example, as well as those portions of the field oxide regions that extend above the top surface of the substrate and the active regions. The step height is thereby eliminated or significantly reduced.

Abstract: STI divot formation is eliminated or substantially reduced by employing a very thin nitride polish stop layer, e.g., no thicker than 400 ?. The very thin nitride polish stop layer is retained in place during subsequent masking, implanting and cleaning steps to form dopant regions, and is removed prior to gate oxide and gate electrode formation.

Abstract: The method performs a first photolithography and etch to form shallow trench isolation features and alignment mark features into the top SOI layer. The shallow trenches are then filled with a dielectric material to form the isolation. A second lithography and etch step is then applied to etch the window locations for back-side contacts, and to transfer the alignment marks down into the SOI lower substrate. After this first lithography and etch step, the alignment marks in the top silicon may be used for alignment of the second lithography mask and etch. This is made possible by leaving the polish stop layer on the wafer, which serves to increase the optically effective thickness of the alignment mark pattern. The polish stop layer is removed after the second etch process. The teachings can be applied to any Semiconductor-On-Insulator-type wafer/technology where the top semiconductor layer is not thicker than the optimum alignment mark depth.

Abstract: In the formation of a semiconductor device, one or more hardmasks are formed during a process for patterning a device feature. One or more of the hardmasks is subjected to an isotropic etch to trim the hardmask prior to patterning an underlying layer. The trimmed hardmask layer is preferably an amorphous carbon layer.

Abstract: A method for forming semiconductor features, e.g., gates, line widths, thicknesses and spaces, produced by a photoresist trim procedure, in a closed loop process is presented. The methodology enables the use of optical emission spectroscopy and/or optical interferometry techniques for endpoint monitoring during resist trim etching of photoresist structures. Various types of material layers underlying photoresist structures are employed in order to provide an endpoint signal to enable closed loop control, with resultant improved targeting of photoresist mask and reproducibility. In addition, the method provides for in situ etch rate monitoring, and is not adversely affected by etch rate variances within an etching chamber during an etch process.

Abstract: A multilayer L-shaped spacer is formed of a lower portion comprising a CVD organic material or amorphous carbon, and an upper portion comprised of a protective material. The upper portion is patterned using a photoresist mask. During that patterning, the underlying substrate is protected by a layer of CVD organic material or amorphous carbon. The CVD organic material or amorphous carbon is then patterned using the patterned protective material as a mask. The chemistry used to pattern the CVD organic material or amorphous carbon is relatively harmless to the underlying substrate. Alternatively, an L-shaped spacer is patterned without using a photoresist mask by forming an amorphous carbon spacer around a gate that is covered with a conformal layer of a conventional spacer material. The conventional spacer material is patterned using the amorphous carbon spacer as an etch mask.

Abstract: A method for fabricating sidewall spacers in the manufacture of an integrated circuit device is disclosed. A dielectric spacer layer is formed over the semiconductor substrate. The dielectric spacer layer is etched prior to forming a layer subsequent to the dielectric layer, to form an L-shaped spacer. In another embodiment, a structure is formed on a substrate, the structure having a sidewall portion that is substantially orthogonal to a surface of the substrate. A dielectric layer is formed over the substrate. A spacer is formed over a portion of the dielectric layer and adjacent to the sidewall portion of the structure, wherein at least a portion of the dielectric layer over the substrate without an overlying oxide spacer is an unprotected portion of the dielectric. At least a part of the unprotected portion of the dielectric layer is removed. An intermediate source-drain region can be formed beneath a portion of the L-shaped spacer by controlling the thickness and/or the source drain doping levels.

Abstract: To reduce the width of a MOSFET gate, the gate is formed with a hardmask formed thereupon. An isotropic etch is then performed to trim the gate in order to reduce the width of the gate. The resulting gate may be formed with a width that is narrower than a minimum width achievable solely through conventional projection lithography techniques.

Abstract: Patterning of a gate line is terminated prior to etching completely through the conductive layer from which it is patterned. Surfaces of the conductive layer are then reacted in a reactive atmosphere, and the reacted surfaces are removed, creating a narrow gate line. The protection provided by the remaining portion of the conductive layer during reaction protects the lower corners of the patterned feature from undercutting growth of reacted material. Alternatively, a gate line is patterned from a multi-layered conductive structure that includes a lower conductive layer and an upper conductive layer that exhibits higher reactivity in a reactive atmosphere than the lower layer. The upper layer is patterned and then the structure is reacted in the reactive atmosphere. Reacted portions of the upper layer are then removed and the lower layer is patterned in a self-aligned manner to complete the formation of a gate line and gate insulator.

Abstract: A layer of material is patterned anisotropically using a bi-layer hardmask structure. Residual photoresist from a photoresist mask used to pattern an upper layer of the bi-layer hardmask is removed prior to patterning of the polysilicon layer. Passivation agents are later introduced from an external source during patterning of the layer of material. This provides a substantially uniform supply of passivation agents to all parts of the layer of material as it is being etched, rather than relying on the generation of passivation agents from consumption of photoresist during etching, which can produce local non-uniformities of passivation agent availability owing to differences in photoresist thickness remaining on different sized features.

Abstract: A method for an integrated circuit includes the use of an amorphous carbon ARC mask. A layer of amorphous carbon material is deposited above a layer of conductive material, and a layer of anti-reflective coating (ARC) material is deposited over the layer of amorphous carbon material. The layer of amorphous carbon material and the layer of ARC material are etched to form a mask comprising an ARC material portion and an amorphous carbon portion. A feature may then be formed in the layer of conductive material by etching the layer of conductive material in accordance with the mask.

Abstract: A silicon oxide stress relief portion is provided between an amorphous carbon hardmask and a polysilicon layer to be etched to form a gate line. The stress relief portion relieves stress between the hardmask and the polysilicon, thereby reducing the risk of delamination of the hardmask prior to patterning of the polysilicon. The stress relief portion may be trimmed prior to patterning and used as an etch mask for patterning the polysilicon. The amorphous carbon hardmasked may be trimmed prior to patterning the stress relief portion to achieve a further reduction in gate line width.

Abstract: A hardmask stack is comprised of alternating layers of doped amorphous carbon and undoped amorphous carbon. The undoped amorphous carbon layers serve as buffer layers that constrain the effects of compressive stress within the doped amorphous carbon layers to prevent delamination. The stack is provided with a top capping layer. The layer beneath the capping layer is preferably undoped amorphous carbon to reduce photoresist poisoning. An alternative hardmask stack is comprised of alternating layers of capping material and amorphous carbon. The amorphous carbon layers may be doped or undoped. The capping material layers serve as buffer layers that constrain the effects of compressive stress within the amorphous carbon layers to prevent delamination. The top layer of the stack is formed of a capping material. The layer beneath the top layer is preferably undoped amorphous carbon to reduce photoresist poisoning.

Abstract: An amorphous carbon layer is implanted with one or more dopants that enhance the etch resistivity of the amorphous carbon to etchants such as chlorine and HBr that are typically used to etch polysilicon. Such a layer may be pattern to form a handmask for etching polysilicon that provides improved pattern transfer accuracy compared to conventional undoped amorphous carbon.

Abstract: The present invention is directed to a method of controlling an etching process used to form a gate electrode on a semiconductor device. In one embodiment, the method comprises forming a layer of silicon dioxide above a semiconducting substrate, and forming a layer of polysilicon above the layer of silicon dioxide. The method further comprises sensing a thickness of the layer of polysilicon and adjusting, based upon the sensed thickness of said layer of polysilicon, at least one parameter of an etching process to be performed on said layer of polysilicon to define a gate electrode of a transistor, said etching process comprised of at least a timed etch process and an endpoint etch process.

Abstract: To reduce the width of a MOSFET gate, the gate is formed with a hardmask formed thereupon. An isotropic etch is then performed to trim the gate in order to reduce the width of the gate. The resulting gate may be formed with a width that is narrower than a minimum width achievable solely through conventional projection lithography techniques.

Abstract: A hardmask stack is comprised of alternating layers of doped amorphous carbon and undoped amorphous carbon. The undoped amorphous carbon layers serve as buffer layers that constrain the effects of compressive stress within the doped amorphous carbon layers to prevent delamination. The stack is provided with a top capping layer. The layer beneath the capping layer is preferably undoped amorphous carbon to reduce photoresist poisoning. An alternative hardmask stack is comprised of alternating layers of capping material and amorphous carbon. The amorphous carbon layers may be doped or undoped. The capping material layers serve as buffer layers that constrain the effects of compressive stress within the amorphous carbon layers to prevent delamination. The top layer of the stack is formed of a capping material. The layer beneath the top layer is preferably undoped amorphous carbon to reduce photoresist poisoning.

Abstract: Methods are presented for fabrication of alignment features of a desired depth, and shallow trench isolation (STI) features in Silicon-On-Insulator (SOI) material. Specific embodiments require no more than two lithography and etch processes, which represents an improvement over current methodology requiring three lithography and etch processes in order to produce the desired features during manufacture of a semiconductor device.