Abstract: A method is provided for manufacturing a semiconductor device on a semiconductor substrate using a dielectric as a bottom anti-reflective coating for formation of a photoresist contact opening which is used to enlarge the Final Inspection Critical Dimension (FICD) of the conductive contact. A high selectivity etch is used to form a tapered contact.

Abstract: An improved method of making a flash memory cell including a substrate having a floating gate of a first thickness includes depositing an insulator on the substrate and over the floating gate. The insulator is preferably a high quality oxide. A portion of the insulator not covering the floating gate has a second thickness which is greater than the first thickness of the floating gate. The method further includes polishing the insulator until the second thickness is substantially equal to the first thickness. Polishing results in a planar floating gate and insulator layer. The method further includes sequentially depositing a dielectric layer and a control gate layer on the planar floating gate and insulator layer and then etching these layers to complete the stacked gate structure of the memory cell.

Abstract: A thin barrier layer of undoped silicon is formed on an ARC to prevent resist poisoning and footing. The silicon layer can be removed with improved yield and high selectivity with respect to the underlying gate dielectric layer, thereby avoiding degradation of the gate dielectric layer. Embodiments include forming a silicon oxynitride ARC on a polycrystalline silicon layer overlying a silicon oxide layer, depositing a thin undoped polycrystalline or amorphous silicon barrier layer on the ARC, forming a photoresist mask on the barrier layer, etching to form a gate electrode on a gate oxide layer and removing the photoresist mask. The undoped polycrystalline or amorphous silicon barrier layer is then removed employing conventional wet or dry etching techniques with high etch selectivity to the underlying gate oxide layer, thereby avoiding degradation of the gate oxide layer.

Abstract: The high density plasma metal etch rate of a conductive material within a dense array of conductive lines is increased to greater than the etch rate of the conductive material in a bordering open field by controlling the source power and the bottom power in a plasma chamber, thereby reducing overetching, resist loss, and oxide loss in the open field, and facilitating planarization.

Abstract: The use of chlorine and oxygen chemistry in a polysilicon etch environment provides a process to etch a plurality of silicon-based layers on a semiconductor substrate to an underlying oxide layer in a single step. The process is useful in the formation of gate structures wherein high selectivity to the underlying oxide layer thereby affords higher processing control over the formed gate structure.

Abstract: A resist mask pattern having a reduced thickness is formed overlying on a silicon oxynitride film during formation of a memory gate. The resist mask pattern has a resist thickness (3000 to 4000 Angstroms) sufficient to withstand removal during etching of the silicon oxynitride film. The silicon oxynitride film, having a thickness of about 800 to 1500 Angstroms, is etched based on the resist mask pattern and then used as a mask pattern to etch the polysilicon gate layer underlying the silicon oxynitride layer, to expose a portion of an isolation region aligned relative to the resist mask pattern. The portion of the resist mask remaining after etching, in combination with the etched silicon oxynitride film, have a sufficient overall thickness to serve as a channel implant mask. Use of the resist mask pattern having the reduced thickness improves yield by minimizing the occurrence of misregistration, and enables reliable formation of spaces in the mask pattern having widths of less than 0.

Abstract: A memory gate stack in a high density memory core has spaces on the order of less than 0.25 microns using conventional deep ultraviolet (DUV) lithography techniques by depositing a layer of silicon oxynitride over a plurality of layers, and a thin resist layer overlying on the silicon oxynitride layer. The resist layer has a thickness sufficient to withstand removal during etching of the silicon oxynitride layer, for example about 3,000 Angstroms to about 4,000 Angstroms. The silicon oxynitride layer has a sacrificial portion having a thickness at least about 500 Angstroms, and a stop-layer thickness, used for spacer formation following etching of the memory gate, of at least 1,000 Angstroms. The use of silicon oxynitride as an antireflective coating layer in combination with the thin resist optimizes the resolution of DUV lithography, enabling formation of spacers having widths less than about 0.24 microns.

Abstract: Memory gate stacks having widths of about 0.18 microns to 0.15 microns are formed by trimming a resist mask pattern, having line widths of about 0.25 microns, to a width of about 0.20 microns. An antireflective coating layer such as silicon oxynitride underlying the resist pattern is then etched to form etched silicon oxynitride pattern lines having widths of about 0.18 to 0.15 microns. The etched silicon oxynitride layer is then used for self-aligned etching of underlying layers to form the memory gate stack. Hence, a memory gate can be formed that has a width substantially less than the current photolithography limit during formation of the resist mask pattern.

Abstract: A method is provided for manufacturing a semiconductor with fewer steps and minimized variation in the etching process by using SiON as a bottom antireflective (BARC) layer and hard mask in conjunction with a thin photoresist layer. In one embodiment, an etch-stop layer is deposited on a semiconductor substrate, a dielectric layer is deposited on top of the etch-stop layer, a BARC is deposited on top of the dielectric layer, and a photoresist layer with a thickness less than the thickness of the BARC is then deposited on top of the BARC. The photoresist is then patterned, photolithographically processed, and developed. The BARC is then etched away in the pattern developed on the photoresist and to photoresist is then removed. The BARC is then used as a mask for the etching of the dielectric layer and is subsequently removed in the process of etchings the dielectric and etch-stop layers without the benefit of a separate BARC-removal step.

Abstract: A thermally grown oxide buffer layer is formed on a silicon layer prior to depositing an ARC thereon, thereby preventing damage to the silicon layer during ARC removal. Embodiments include thermally growing a silicon oxide buffer layer on an amorphous or polycrystalline silicon layer by thermal oxidation at a temperature of about 800° C. to about 900° C. in an atmosphere comprising oxygen or steam. A silicon oxynitride or silicon-rich silicon nitride ARC is then formed on the thermally grown protective silicon oxide buffer layer and a photoresist layer is formed on the ARC. The photoresist layer is patterned to form a mask and the underlying silicon layer etched to form a conductive feature, e.g., gate electrode. The photoresist mask is then removed and the ARC is stripped with hot phosphoric acid or by dry etching, while the thermally grown silicon oxide buffer layer protects the underlying silicon layer from damage.

Abstract: In the manufacture of sub-0.35 micron semiconductors using deep ultraviolet lithography, a bilayer of silicon dioxide on top of silicon oxynitride is used as bottom anti-reflective coating and an etch hard mask for photolithographic resist. Since the silicon dioxide is optically transparent at the deep ultraviolet wavelengths being used (248 nm), its thickness in combination with a preselected reflective silicon oxynitride thickness satisfies the zero reflectivity goal and, at the same time, is adequately thick to serve as a hard mask for self-aligned etch and self-aligned-source etch.

Abstract: An oxide buffer layer is formed between an underlying silicon layer and overlying ARC to prevent damage to the silicon layer when removing the ARC. Embodiments include depositing a silicon oxide buffer layer on an amorphous or polycrystalline silicon layer by PCVD, LPCVD or high temperature CVD, forming a SiON or Si-rich SiN ARC on the silicon oxide buffer layer, forming a photoresist mask on the ARC, patterning the underlying silicon layer to form a conductive line or gate electrode, stripping the photoresist mask and then stripping the ARC with hot phosphoric acid while the silicon oxide buffer layer protects the underlying silicon feature from pitting.

Abstract: A hard resist layer is formed on and/or within a deep-UV configured resist mask prior to patterning a semiconductor device feature. The hard resist layer reduces the amount of polymer residue generated during the patterning process, which can effect the resulting profile of the device feature. The hard resist mask is formed by either ion implantation or plasma treatments. Due to the formation of the hard resist layer, the thickness of the resist mask can be reduced, thereby increasing the resolution capabilities of the resist mask.

Abstract: In the manufacture of sub 0.35 micron semiconductors using deep ultraviolet lithography, a bilayer of silicon dioxide on top of silicon oxynitride is used as bottom anti-reflective coating and an etch hard mask for photolithographic resist. Since the silicon dioxide is optically transparent at the deep ultraviolet wavelengths being used (248 nm), its thickness in combination with a preselected reflective silicon oxynitride thickness satisfies the zero reflectivity goal and, at the same time, is adequately thick to serve as a hard mask for self-aligned etch and self-aligned-source etch.

Abstract: A hard resist layer is formed on and/or within a deep-UV configured resist mask prior to patterning a semiconductor device feature. The hard resist layer reduces the amount of polymer residue generated during the patterning process, which can affect the resulting profile of the device feature. The hard resist mask is formed by subjecting the resist mask to a rapid thermal anneal (RTA) type of process. Because of the hard resist layer, the thickness of the resist mask can also be reduced, thereby increasing the resolution capabilities of the resist mask.

Abstract: A defective photoresist mask is removed from a metal layer prior to etching by low-temperature processing to minimize or substantially eliminate any resulting residue on the metal layer, thereby enabling the formation of an interconnection pattern with minimal defects. Embodiments include removing the defective mask by applying a solvent at a temperature of about 80° C. or less, forming a new photoresist mask, and etching the underlying metal layer. The substantial elimination of residue on the metal layer prior to etching avoids bridging between resulting interconnection lines and, hence, short circuiting and device failure.

Abstract: A multistage etching process is provided for etching through portions of a layer stack during the formation of a control gate in a semiconductor device. The multistage etching process allows for controlled removal of a tungsten silicide layer within the layer stack by reducing the potential for loading, microloading, over-etching, under-etching, etc. In a first stage of the multistage etching process, part of the tungsten silicide layer is selectively etched away using a plasma that exhibits an etching selectivity (ratio of tungsten silicide etch rate to polysilicon etch rate) less than about 1.2. During the second stage of the multistage etching process, the remaining amount and/or residue parts of the tungsten silicide layer is selectively etched away using a plasma that exhibits an etching selectivity (ratio of tungsten silicide etch rate to polysilicon etch rate) greater than about 1.2.

Abstract: Polysilicon and oxide layers on a semiconductor wafer are etched in a single etching chamber configured for selectively providing a first etching environment in the chamber for etching of the polysilicon layer, and a second etching environment in the chamber for etching the oxide layer. The decoupled plasma source polysilicon etch chamber enables etching of both oxide-based layers and silicon-based layers, without removing the semiconductor wafer from the etching chamber.

Abstract: A resist mask pattern having a reduced thickness is formed overlying on a silicon oxynitride film during formation of a memory gate. The resist mask pattern has a resist thickness (3000 to 4000 Angstroms) sufficient to withstand removal during etching of the silicon oxynitride film. The silicon oxynitride film, having a thickness of about 800 to 1500 Angstroms, is etched based on the resist mask pattern and then used as a mask pattern to etch the polysilicon gate layer underlying the silicon oxynitride layer, to expose a portion of an isolation region aligned relative to the resist mask pattern. The portion of the resist mask remaining after etching, in combination with the etched silicon oxynitride film, have a sufficient overall thickness to serve as a channel implant mask. Use of the resist mask pattern having the reduced thickness improves yield by minimizing the occurrence of misregistration, and enables reliable formation of spaces in the mask pattern having widths of less than 0.

Abstract: An etching process is provided for etching through a tungsten silicide layer and an underlying polysilicon layer during the formation of a control gate in a semiconductor device. The etching process prevents the formation of a tungsten silicide residue while etching a layer of tungsten silicide, by employing a plasma that exhibits strong physical sputtering capabilities. The plasma effectively etches away exposed portions of the silicide layer, especially in narrow patterned regions. The plasma exhibits an etching selectivity (ratio of tungsten silicide etch rate to polysilicon etch rate) that is less than about 1.0.