Abstract: The preferred embodiment provides a method for forming unlinked features when using image enhancement techniques. The preferred method is particularly applicable for use in hybrid resist lithographic processes. The method uses a trimming feature embedded in a substrate. The trimming feature acts as a block during a selective etch. This results in unlinked trenches being formed in the substrate. Thus, the preferred method creates unlinked, separate trenches from the “loops” formed by the hybrid resist or other image enhancement techniques. This allows the preferred method to form a plurality of unlinked features rather than the loops or linked features without requiring additional processing steps.

Abstract: A MOSFET device and a method of manufacturing the device. The device has a trench formed in a silicon substrate. The channel of the device is at the bottom of the trench. Diffusion layers are formed adjacent to opposite sides of the trench. Each diffusion layer is connected to the edge of the device channel by extending the diffusion layer along the side wall of the trench and under a portion of the trench.

Abstract: The present invention provides methods of forming an out-diffused bitline in a semiconductor substrate by utilizing a laser annealing step wherein the dopant material in the trench region is out-diffused into the semiconductor substrate. The out-diffused bitline can also be formed utilizing an ion implantation step.

Abstract: A method for forming a gate conductor cap in a transistor comprises the steps of: a) forming a polysilicon gate conductor; b) doping the polysilicon gate; c) doping diffusion areas; and d) capping the gate conductor by a nitridation method chosen from among selective nitride deposition and selective surface nitridation. The resulting transistor may comprise a capped gate conductor and borderless diffusion contacts, wherein the capping occurred by a nitridation method chosen from among selective nitride deposition and selective surface nitridation and wherein a portion of the gate conductor is masked during the nitridation method to leave open a contact area for a local interconnect or a gate contact.

Abstract: The present invention overcomes the limitations of the prior art to allow for the creation of smaller components for use in logic circuits. The invention provides a new method of defining and forming features on a semiconductor substrate by using a layer of material, referred to as a shadow mandrel layer, to cast a shadow. A trough is etched in the shadow mandrel layer. At least one side of the trough will be used to cast a shadow in the bottom of the trough. A conformally deposited photoresist is used to capture the image of the shadow. The image of the shadow is used to define and form a feature. This allows for the creation of images on the surface of a wafer without the diffraction effects encountered in conventional photolithography. This allows for a reduced device size and increased chip operating speed.

Abstract: A bottle-shaped trench capacitor with a buried plate is formed in a controlled etch process. The bottle-shape is fabricated by etching deep trenches from a layered substrate, using the layers as a mask, and covering the side walls of the substrate with protective oxide and nitride layers. With the side walls covered, deep trench etching is then resumed, and a lower trench portion, below the protective layers of the side wall are formed. By diffusing a first dopant in the lower portion of the deep trench region, using the side wall protective layers as a mask, an etch stop is established for a wet etch process at the p/n junction established by the first dopant. The width of the lower trench portion is regulated by the time and temperature of the diffusion. Removing the doped material and applying a second dopant to the lower trench portion establishes a continuous buried plate region between trenches. A capacitor is formed by applying an insulating layer to the trench and filling with a conductor.

Abstract: The preferred embodiment of the present invention overcomes the limitations of the prior art and provides a method to form spaces in hybrid resist with varying widths. In particular, the preferred method facilitates the formation of spaces with different widths by using mask shapes (either openings or lines) that are smaller than the diffraction limit of the photolithography tool. Diffraction effects at these dimensions reduce the light intensity reaching the resist surface such that the hybrid resist receives an intermediate exposure. These portions of hybrid resist that receive an intermediate exposure are soluble in developer and thus develop away to form spaces in the hybrid resist. Thus, spaces in the hybrid resist of varying widths can be formed.

Abstract: A method for forming square shape images in a lithographic process is disclosed wherein a first plurality of lines running in a first direction is defined in a first, usually sacrificial, layer, and then a second resist is defined wherein the lines run in an intersecting pattern to those of the first layer, thereby creating cornered images wherever the first and second layer intersect and in the open areas between the lines. Methods are proposed for developing the square intersecting areas and the square angle areas defined by the openings. Additionally, a photomask is disclosed in which the length and width of the cornered images are independently patterned using the two-exposure process.

Abstract: A trench storage dynamic random access memory cell with vertical transfer device can be formed in a wafer having prepared shallow trench isolation. Vertical transfer device is built as the deep trenches are formed. Using square printing to form shallow trench isolation and deep trenches, allows for scaling of the cell to very small dimensions.

Abstract: It is a feature of the present invention that a subminimum dimension wordline links approximately minimum dimensional individual gate segments with the bitline contact being borderless to the worldline. It is still a further object of the present invention to provide a transistor with an individual segment gate conductor and a subminimum dimension gate connector with the bitline contact being borderless to the wordline. A semiconductor structure and method of making same comprising a DRAM cell which has a transistor which includes a gate. The gate comprises an individual segment of gate conductor such as polysilicon on a thin dielectric material. The transistor further comprises a single crystal semiconductor substrate having a source/drain region. An active conductive wordline is deposited on top of and electrically contacting the segment gate conductor with the wordline being a conductive material.

Abstract: The present invention provides for an improved method of creating vias and trenches during microchip fabrication. According to the invention, the vias and trenches are self-aligned during the photolithography process by using two layers of specially selected resists and exposing the resists such that the lower resist is exposed only where an opening has been formed in the upper resist layer. This self-aligning enables the vias to be printed as elongated shapes, which allows for the use of particularly effective image enhancement techniques. The invention further provides a simplified procedure for creating vias and trenches, in that only one etch step is required to simultaneously create both vias and trenches. An alternative embodiment of the invention allows looped or linked images, such as those printed using image enhancement techniques, to be trimmed to form isolated features.

Abstract: A DRAM device and a process of manufacturing the device. The DRAM device includes a bit-line coupled to a signal storage node through a transfer device that is controlled by a word line. The transfer device includes a mesa structure having a first end, a second end opposite the first end, a top, a first side, and a second side opposite the first side. A bit-line diffusion region couples the first end of the mesa structure to a bit-line contact. A storage node diffusion region couples the second end of the mesa structure to the signal storage node. The word line controls a channel formed in the mesa structure through a gate which is formed upon the first side, the second side, and the top of the mesa structure. A sub-minimum width of the mesa structure allows full depletion to be easily achieved, resulting in volume inversion in the channel.

Abstract: A semiconductor structure and method of making the same are disclosed which includes a DRAM cell which has a transistor which includes a gate. The gate includes an individual segment of gate conductor such as polysilicon on a thin dielectric material. The transistor further has a single crystal semiconductor substrate having a source/drain region. An active conducting wordline is deposited on top of and electrically contacting a segment gate conductor, the wordline being a conductive material having a top and sidewalls. Electrically insulating material completely surrounds the active wordline except where the active wordline contacts the segment gate conductor. The insulating material surrounding the active wordline includes silicon nitride overlying the top and surrounding a portion of the sidewalls thereof, and silicon dioxide surrounds the remainder of the side walls of the active wordline.

Abstract: A photoresist composition is disclosed having both negative tone and positive tone responses, giving rise to spaces being formed in the areas of diffraction which are exposed to intermediate amounts of radiation energy. This resist material may be used to print doughnut shapes or may be subjected to a second masking step, to print lines. Additionally, larger and smaller features may be obtained using a gray-scale filter in the reticle, to create larger areas of intermediate exposure areas.

Abstract: A densely packed array of vertical semiconductor devices having pillars and methods of making thereof are disclosed. The array has rows of wordlines and columns of bitlines. The array has vertical pillars, each having two wordlines, one active and the other passing for each cell. Two wordlines are formed per pillar on opposite pillar sidewalls which are along the row direction. The threshold voltage of the pillar device is raised on the side of the pillar touching the passing wordline, thereby permanently shutting off the pillar device during the cell operation and isolating the pillar from the voltage variations on the passing wordline. The isolated wordlines allow individual cells to be addressed and written via direct tunneling, in both volatile and non-volatile memory cell configurations. For Gbit DRAM application, stack or trench capacitors may be formed on the pillars, or in trenches surrounding the pillars, respectively.

Abstract: Five square dynamic random access memory (DRAM) cell is prepared with a vertical transfer device with long channel length. In this construction, channel length is not affected by cell size scaling requirements.

Abstract: The present invention provides a method for forming self-aligned spacers on the horizontal surfaces while removing spacer material from the vertical surfaces. The preferred method uses a resist that can be made insoluble to developer by the use of an implant. By conformally depositing the resist over a substrate having both vertical and horizontal surfaces, implanting the resist, and developing the resist, the resist is removed from the vertical surfaces while remaining on the horizontal surfaces. Thus, a self-aligned spacer is formed on the horizontal surfaces while the spacer material is removed from the vertical surfaces. This horizontal-surface spacer can then be used in further fabrication. The preferred method can be used in many different processes where there is exists a need to differentially process the vertical and horizontal surfaces of a substrate.

Abstract: The preferred embodiments of the present invention overcome the limitations of the prior art by providing a method for forming the source/drain diffusions in a vertical transistor structure that results in improved channel length uniformity. In one embodiment, the present invention is used to form source/drain and bitline diffusion structures for use in pillar memory cells. Additionally, in another embodiment, the present invention is used to form source/drain and plate diffusion structures in pillar memory cells. Both preferred embodiments deposit conformal photoresist on a pillar structure and use an off-axis exposure process to recess a dopant source layer to the proper depth along the pillar. The recessed dopant source layer can then be used to form the source/drain/bitlines diffusions or source/drain/plate diffusions in the pillar memory device.

Abstract: The present invention overcomes the difficulties found in the background art by providing a direct low resistive contact between devices on a semiconductor chip without excessive current leakage. Current leakage is prevented in the preferred design by using silicon on insulator (SOI) construction for the chip. By constructing the direct contact over an insulator, such as silicon dioxide, current leakage is minimized. The preferred embodiment uses silicide to connect a polysilicon gate to a doped region of the substrate. An alternative embodiment of the present invention provides for the use of conductive studs to electrically connect devices. An increased density of approximately twenty percent may be realized using the present invention.

Abstract: A memory cell having a grooved gate formed in a sub-lithographic groove, and methods of making thereof are disclosed. The groove extends the channel length to include the groove sidewalls and width of the groove. Sidewall sections of the channel located along the gate sidewalls have a larger length than the bottom channel section length located along the gate bottom width. Thus, the memory device is primarily controlled by the sidewall channel sections, instead of the bottom channel section. The groove may be a stepped groove formed by a two step etch to further increase the channel length and may be formed centered along the gate conductor width.