A method for fabricating double-gate and tri-gate transistors in the same process flow is described. In one embodiment, a sacrificial layer is formed over stacks that include semiconductor bodies and insulative members. The sacrificial layer is planarized prior to forming gate-defining members. After forming the gate-defining members, remaining insulative member portions are removed from above the semiconductor body of the tri-gate device but not the I-gate device. This facilitates the formation of metallization on three sides of the tri-gate device, and the formation of independent gates for the I-gate device.
RELATED APPLICATIONS
This patent application is a continuation-in-part of U.S. patent application Ser. No. 10/955,670, filed Sep. 29, 2004, entitled INDEPENDENTLY-ACCESSED DOUBLE-GATE AND TRI-GATE TRANSISTORS IN SAME PROCESS FLOW, by Brian S. Doyle.
A resistive memory cell random access memory device and method for fabrication. In one embodiment, the invention relates to a resistive memory cell random access memory device comprising a plurality of first current lines; a plurality of second current lines; a plurality of third current lines being formed as split current lines; and an array of resistive memory cells arranged in columns defined by said first current lines and rows defined by said third current lines, each resistive memory cell including a resistive memory element and an access transistor connected in series, each memory cell being connected between one of said first current lines and a reference potential, wherein said access transistors being FinFET-type field effect transistors, each one having two independent gates and a common floating body, and wherein each third current line being connected to one of said two independent gates of each one of the access transistors of a row of said array and being connected to one of said two independent gates of each one of the access transistors of an adjacent row of said array. It also relates to a method for its fabrication.
A field effect transistor (FET) device structure and method for forming FETs for scaled semiconductor devices. Specifically, FinFET devices are fabricated from silicon-on-insulator (SOI) wafers in a highly uniform and reproducible manner. The method facilitates formation of FinFET devices with improved and reproducible fin height control while providing isolation between source and drain regions of the FinFET device.
Disclosed is an integrated circuit with multiple semiconductor fins having different widths and variable spacing on the same substrate. The method of forming the circuit incorporates a sidewall image transfer process using different types of mandrels. Fin thickness and fin-to-fin spacing are controlled by an oxidation process used to form oxide sidewalls on the mandrels, and more particularly, by the processing time and the use of intrinsic, oxidation-enhancing and/or oxidation-inhibiting mandrels. Fin thickness is also controlled by using sidewalls spacers combined with or instead of the oxide sidewalls. Specifically, images of the oxide sidewalls alone, images of sidewall spacers alone, and/or combined images of sidewall spacers and oxide sidewalls are transferred into a semiconductor layer to form the fins. The fins with different thicknesses and variable spacing can be used to form a single multiple-fin FET or, alternatively, various single-fin and/or multiple-fin FETs.
Dual-gate memory cells and tri-gate CMOS devices are integrated on a common substrate. A plurality of silicon bodies are formed from a monocrystalline silicon on the substrate to define a plurality of transistors including dual-gate memory cells, PMOS transistors, and NMOS transistors. An insulative layer is formed overlying the silicon body of the memory cell. A layer of a high-k dielectric and at least a metal layer cover the silicon bodies and their overlying layers. Next, gain regions of the transistors are filled with polysilicon. Thus, a gate is formed on the top surface and both sidewalls of a tri-gate transistor. Thereafter, the high-k dielectric and the metal layer overlying the insulative layer of the memory cell are removed to expose the insulative layer. Thus, two electrically-isolated gates of the memory cell are formed.