摘要:
A method of forming an LDD field effect transistor with an inverted "T"-gate structure in which consecutive, conformal layers of polysilicon, metal and nitride or oxide are deposited to fill the recess in a composite interconnect layer on top of a trench isolated region of a semiconductor substrate. These conformal layers successively decrease in thickness and are selectively etched in two steps to form a self-aligned inverted T structure. A first reactive ion etch (RIE) step preferentially etches the exposed outer polysilicon to a certain depth. During a second step RIE the polysilicon layer is completely etched down to the a gate oxide surface and the metal layer is preferentially etched so that subtends only the remaining nitride or oxide cap.
摘要:
A lightly doped drain, field effect transistor with an inverted "T"-gate structure has a gate electrode disposed on a polysilicon pad in a stack opening. The inner edge of a lightly-doped source and drain region is aligned with the gate electrode and its outer edge is aligned with an edge of the polysilicon pad. The inner edge of a heavily-doped source and drain region is aligned with the edge of the edge of the polysilicon pad and its outer edge is aligned with the wall surface that forms the opening. The inner edge of a source and drain contact region is aligned with the wall and extends under the stack.
摘要:
A trench capacitor DRAM cell with Shallow Trench Isolation (STI), a self-aligned buried strap and the method of making the cell. A trench capacitor is defined in a substrate. The trench capacitor's polysilicon (poly) plate is recessed below the surface of the substrate and the trench sidewalls are exposed above the poly. A doped poly layer is deposited over the surface contacting both the sidewall and the trench capacitor's poly plate. Horizontal portions of the poly layer are removed either through chemmech polishing or Reactive Ion Etching (RIE). A shallow trench is formed, removing one formerly exposed trench sidewall and a portion of the trench capacitor's poly plate in order to isolate the DRAM cell from adjacent cells. The remaining poly strap, along the trench sidewall contacting the poly plate, is self aligned to contact the source of the DRAM Pass gate Field Effect Transistor (FET). After the shallow trench is filled with oxide, FET's are formed on the substrate, completing the cell. In an alternate embodiment, instead of recessing the poly plate, a shallow trench is formed spanning the entire width of the trench capacitor. The deposited polysilicon is selectively removed, having straps that strap the poly plate to the shallow trench sidewall.
摘要:
A method of forming a MOS DRAM cell having a trench capacitor in which the strap connection to the trench capacitor, the source, drain, and isolation are all raised above the surface of the single crystal silicon includes the steps of forming the trench capacitors, depositing a blanket gate stack including the gate oxide and a set of gate layers, and then depositing isolation members in apertures etched in the gate stack using the gate oxide as an etch stop. The same sidewalls that are used to form an LDD source and drain form a self-aligned aperture for a surface strap that insulates the strap from misaligned portions of the gate stack.
摘要:
A method of forming a MOS FET in which the source, drain, and isolation are all raised above the surface of the single crystal silicon includes the steps of depositing a blanket gate stack including the gate oxide and a set of gate layers, and then depositing isolation members in apertures etched in the gate stack using the gate oxide as an etch stop. The sidewalls that are used to form an LDD source and drain separate a gate contact from source and drain contacts.
摘要:
A shallow trench isolation structure is formed by a process having a reduced number of steps and thermal budget by filling trenches by liquid phase deposition of an insulating semiconductor oxide and heat treating the deposit to form a layer of high quality thermal oxide at an interface between the deposited oxide and the body of semiconductor material (e.g. substrate) into which the trench extends. This process yields an isolation structure with reduced stress and reduced tendency to develop charge leakage. The structure can be readily and easily planarized, particularly if a polish-stop layer is applied over the body of semiconductor material and voids and contamination of the deposited oxide are substantially eliminated by self-aligned deposition above the trench in the volume of apertures on a resist used to form the trench.
摘要:
A method of forming a MOS DRAM cell having a trench capacitor in which the strap connection to the trench capacitor, the source, drain, and isolation are all raised above the surface of the single crystal silicon includes the steps of forming the trench capacitors, depositing a blanket gate stack including the gate oxide and a set of gate layers, and then depositing isolation members in apertures etched in the gate stack using the gate oxide as an etch stop. The same sidewalls that are used to form an LDD source and drain combine with nitride sidewalls on a gate contact aperture to separate a gate contact from source and drain contacts.
摘要:
A conductor bit line for a dynamic random access memory (RAM) structure is formed of a material selected from the group consisting of polycrystalline silicon and a metal silicide, polycrystalline silicon and a conductive metal, and polycrystalline silicon, a metal silicide, and a conductive metal with the polycrystalline silicon contacting at least a portion of the drain region of the field effect transistor of each of a plurality of cells of the RAM structure via a self-aligned contact. When the selected material is polycrystalline silicon and a metal silicide, the conductor bit line is continuous. When the selected material is polycrystalline silicon and a conductive metal or polycrystalline silicon, a metal silicide, and a conductive metal, the polycrystalline silicon contacts with each of the drain regions while the conductive metal connects the polycrystalline silicon overlying adjacent drain regions when the selected material is polycrystalline silicon and a conductive metal and connects the metal silicide on the polycrystalline silicon overlying adjacent drain regions when the selected material is polycrystalline silicon, a metal silicide, and a conductive metal.
摘要:
A semiconductor body having surface regions thereof isolated from other such regions by a pattern of dielectric isolation is provided. At least two narrow widths PN junction regions are located within at least one of the surface regions. Each PN junction has a width dimension substantially that of its electrical contact. Substantially vertical conformal conductive layers electrically ohmic contact each of the PN junction regions. The PN junction regions are the emitter and collector regions for a lateral bipolar transistor. A base PN junction region of an opposite conductivity is located between and contiguous to the emitter and the collector junctions. Substantially horizontal conductive layers are in electrical contact with an edge of each of the vertical conductive layers and separated from the surface regions by a first electrical insulating layer. A second insulating layer covers the conformal conductive layers. The horizontal conductive layer is patterned so as to have electrically separated conductive lines from one another. A third electrical insulating layer is located over the patterned horizontal conductive layers. An electrical contact is made to each of the horizontal conductive layers through an opening in the third electrical insulating layer which effectively makes contacts to the emitter and collector regions through the patterned horizontal conductive layers and the vertical conductive layers. An ohmic contact is made to the base region which is separated from the vertical conductive layers by the second insulating layer.
摘要:
A capacitor is provided having a substrate and a first capacitor plate including a lattice mismatched crystalline material is formed over and supported by a surface of the substrate. A layer of insulating material is formed over and supported by the first capacitor plate. A second capacitor plate including a layer of conductive material is formed over and supported by the layer of insulating material.