Abstract:
A method of manufacturing a semiconductor device includes providing a silicon semiconductor layer (14) over an insulating layer (12), and partially removing a first portion of the silicon layer (14). The silicon layer (14) includes the first portion and a second portion, and a thickness of the second portion is greater than a thickness of the first portion. Initially, the first and second portions of the silicon layer (14) initially can have the same thickness. A semiconductor device is also disclosed.
Abstract:
An isolation technique is provided for improving the overall planarity of isolation regions relative to adjacent active area silicon mesas. The isolation process results in a trench formed in field regions immediately adjacent the active regions. The trench, however, does not extend entirely across the field region. By preventing large area trenches, substantial dielectric fill material and the problems of subsequent planarization of that fill material is avoided. Accordingly, the present isolation technique does not require conventional fill dielectric normally associated with a shallow trench process. While it achieves the advantages of forming silicon mesas, the present process avoids having to rework dielectric surfaces in large area field regions using conventional sacrificial etchback, block masking and chemical-mechanical polishing. The improved isolation technique hereof utilizes trenches of minimal width etched into the silicon substrate at the periphery of field regions, leaving a field mesa. A field dielectric, preferably oxide, is formed upon the field mesa and fills trenches between the field mesa and active mesas, leaving a substantially planar field dielectric commensurate with the upper surface of adjacent active mesas.
Abstract:
An isolation technique is provided for improving the overall planarity of trench isolation regions relative to adjacent silicon mesas. The isolation process results in a spaced plurality of field dielectric having an upper surface substantially coplanar with each other and with adjacent silicon mesa upper surfaces. The isolation process is thereby a planarization process used with the shallow trench technique, wherein etch-enhancing ions are forwarded into the fill dielectric at upper elevational regions of that dielectric. When subjected to a subsequent etchant, the dopants cause the higher elevational regions to be removed at a faster rate than the lower elevational regions. Thus, selective placement of dopants and etch removal pre-conditions the fill dielectric upper surface to a more planar surface globally across the entire wafer. After etch removal predominantly at the higher elevational regions, the remaining fill dielectric upper surface is removed to a level commensurate with the upper surface of silicon mesas thereby producing separate field dielectrics interposed between silicon mesas. The field dielectrics, regardless of their lateral area, each have a substantially planar upper surface at or slightly below the adjoining silicon mesas. By producing planar field dielectric upper surfaces, various problems of non-planarity are removed from the thin films which are thereafter formed on the field dielectrics or between the field dielectrics and silicon mesas.
Abstract:
An improved multilevel interconnect structure is provided. The interconnect structure includes several levels of conductors, wherein conductors (104) on one level are staggered with respect to conductors (106) on another level. In densely spaced interconnect areas, interposed conductors (104) are burried in intermetallic dielectric layer (103) drawn to dissimilar elevational levels to lessen the capacitive coupling between the interconnects.
Abstract:
A photolithography mask derivation process is provided for improving the overall planarity of interlevel dielectric deposited upon conductors formed by the derived photolithography mask. The photolithography mask is derived such that non-operational (dummy) conductors are spaced a minimum distance from each other and from operational conductors to present a regular spaced arrangement of conductors upon which a dielectric layer can be deposited and readily planarized using, for example, chemical-mechanical polishing techniques. The resulting interlevel dielectric upper surface is globally planarized to an even elevational level across the entire semiconductor topography. The operational conductors are dissimilar from non-operational conductors in that the operational conductors are connected within a circuit path of an operational integrated circuit. Non-operational conductors are not connected within the integrated circuit path and generally are floating or are connected to a power supply. The non-operational conductors thereby do not contribute to the integrated circuit functionality other than to provide structural planarity to the overlying interlevel dielectric. The mask derivation process is applicable to either a metal interconnect photolithography mask or a polysilicon interconnect photolithography mask.
Abstract:
A method includes forming a plurality of functional features (210, 410) on a semiconductor layer (205, 405) in a first region. A non-functional feature (240, 415) corresponding to the functional feature (210, 410) is formed adjacent at least one of the functional features (210, 410) disposed on a periphery of the region. A stress- inducing layer (300, 500) is formed proximate the functional features (210, 410) and the non-functional feature (240, 415). A device (200, 400) includes a semiconductor layer (205, 405), a plurality of transistor elements (210, 410), a first dummy gate electrode (240A, 415A), and a stress-inducing layer (300, 500). The plurality of transistor elements (210, 410) is formed above the semiconductor layer (205, 405). The plurality includes at least a first end transistor element (210A, 410A), a second end transistor element (210D, 410C), and at least one interior transistor element (210B, 21 OC, 410B). The first dummy gate electrode (240A, 415A) is disposed proximate the first end transistor element (210A, 415A). The stress-inducing layer (300, 500) is disposed proximate the plurality of transistor elements (210, 410) and the first dummy gate electrode (240A, 415A).
Abstract:
A reticle (130) provides an image pattern and compensates for a lens error in a photolithographic system. The reticle is structurally modified using image displacement data indicative of the lens error. The reticle can be structurally modified by adjusting the configuration (or layout) of radiation-transmitting regions (132, 134) for instance by adjusting a chrome pattern on the top surface of a quartz base. Alternatively, the reticle can be structurally modified by adjusting the curvature of the reticle, for instance by providing a chrome pattern on the top surface of a quartz base and grinding away portions of the bottom surface of the quartz base. The image displacement data may also vary as a function of lens heating so that the reticle compensates for lens heating associated with the reticle pattern.
Abstract:
An improved multilevel interconnect structure is provided. The interconnect structure includes several levels of conductors (12, 14), wherein conductors on one level are staggered with respect to conductors on another level. In densely spaced interconnect areas, interposed conductors are drawn to dissimilar elevational levels to lessen the capacitive coupling between the interconnects. The conductors and vias are made by a damascene process. By staggering every other interconnect line in the densely patterned areas, the interconnects are capable of carrying a larger amount of current with minimal capacitive coupling therebetween.
Abstract:
The present invention is directed to methods of forming contact openings. In one illustrative embodiment, the method includes forming a feature (20) above a semiconducting substrate (22), forming a layer stack comprised of a plurality of layers of material above the feature (22), the layer stack having an original height (32), reducing the original height (32) of the layer stack to thereby define a reduced height (32A) layer stack above the feature, forming an opening (38) in the reduced height layer (32A) stack for a conductive member (40) that will be electrically coupled to the feature (20) and forming the conductive member (40) in the opening (30) in the reduced height (32A) layer stack.
Abstract:
A method of forming a semiconductor device provides a gate electrode (22) on a substrate (20) and forms a polysilicon reoxidation layer (26) over the substrate (20) and the gate electrode (22). A nitride layer (28) is deposited over the polysilicon reoxydation layer (26) and anisotropically etched. The etching stops on the polysilicon reoxidation layer (26), with nitride offset spacers (30) being formed on the gate electrode (22). The use of the polysilicon reoxidation layer (26) as an etch stop layer prevents the gouging of the silicon substrate (20) underneath the nitride layer (28), while allowing the offset spacers (30) to be formed.