Motivated by emerging battery-operated applications that demand intensive computation in portable environments, techniques are investigated which reduce power consumption in CMOS digital circuits while maintaining computational throughput. Techniques for low-power operation are shown which use the lowest possible supply voltage coupled with architectural, logic style, circuit, and technology optimizations. An architecturally based scaling strategy is presented which indicates that the optimum voltage is much lower than that determined by other scaling considerations. This optimum is achieved by trading increased silicon area for reduced power consumption. >

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Low-power CMOS digital design

An object is to provide a semiconductor device of which a manufacturing process is not complicated and by which cost can be suppressed, by forming a thin film transistor using an oxide semiconductor film typified by zinc oxide, and a manufacturing method thereof. For the semiconductor device, a gate electrode is formed over a substrate; a gate insulating film is formed covering the gate electrode; an oxide semiconductor film is formed over the gate insulating film; and a first conductive film and a second conductive film are formed over the oxide semiconductor film. The oxide semiconductor film has at least a crystallized region in a channel region.

Semiconductor device, and manufacturing method thereof

A method of providing a conformal layer of TiSix atop a semiconductor wafer within a chemical vapor deposition reactor includes the following steps: a) positioning a wafer within the reactor; b) injecting selected quantities of gaseous Ti(NR2)4 precursor, gaseous silane and a carrier gas to within the reactor, where R is selected from the group consisting of H and a carbon containing radical, the quantities of Ti(NR2)4 precursor and silane being provided in a volumetric ratio of Ti(NR2)4 to silane of from 1:300 to 1:10, the quantity of carrier gas being from about 50 sccm to about 2000 sccm and comprising at least one noble gas; and c) maintaining the reactor at a selected pressure and a selected temperature which are effective for reacting the precursor and silane to deposit a film on the wafer, the film comprising a mixture of TiSix and TiN, the selected temperature being from about 100° C. to about 500° C., and the selected pressure being from about 150 mTorr to about 100 Torr.

Chemical vapor deposition technique for depositing titanium silicide on semiconductor wafers

This paper examines the apparent limits, possible extensions, and applications of CMOS technology in the nanometer regime. Starting from device scaling theory and current industry projections, we analyze the achievable performance and possible limits of CMOS technology from the point of view of device physics, device technology, and power consumption. Various possible extensions to the basic logic and memory devices are reviewed, with emphasis on novel devices that are structurally distinct front conventional bulk CMOS logic and memory devices. Possible applications of nanoscale CMOS are examined, with a view to better defining the likely capabilities of future microelectronic systems. This analysis covers both data processing applications and nondata processing applications such as RF and imaging. Finally, we speculate on the future of CMOS for the coming 15-20 years.

Nanoscale CMOS

This paper describes a new design methodology to analyzethe on-chip power supply noise for high-performance microprocessors.Based on an integrated package-level andchip-level power bus model, and a simulated switching circuitmodel for each functional block, this methodology offersthe most complete and accurate analysis of Vdd distributionfor the entire chip. The analysis results not only providedesigners with the inductive ΔI noise and the resistive IRdrop data at the same time, but also allow designers to easilyidentify the hot spots on the chip and ΔV across the chip.Global and local optimization such as buffer sizing, powerbus sizing, and on-chip decoupling capacitor placement canthen be conducted to maximize the circuit performance andminimize the noise.

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Power supply noise analysis methodology for deep-submicron VLSI chip design

Electrical fuse (eFUSE) has become a popular choice to enable memory redundancy, chip identification and authentication, analog device trimming, and other applications. We will review the evolution and applications of electrical fuse solutions for 180 nm to 45 nm technologies at IBM, and provide some insight into future uses in 32 nm technology and beyond with the eFUSE as a building block for the autonomic chip of the future.

Electrically Programmable Fuse (eFUSE): From Memory Redundancy to Autonomic Chips

A method and structure for selectively growing epitaxial silicon in a trench formed within a silicon-on-insulator (SOI) structure. The SOI structure includes a buried oxide layer (BOX) on a bulk silicon substrate, and a silicon layer on the BOX. A pad layer is formed on the silicon layer. The pad layer includes a pad nitride (e.g., silicon nitride) on a pad oxide (e.g., silicon dioxide), and the pad oxide has been formed on the silicon layer. A trench is formed by anisotropically etching through the pad layer, the silicon layer, the BOX, and to a depth within the bulk silicon substrate. Insulative spacers are formed on sidewalls of the trench. An epitaxial silicon layer is grown in the trench from a bottom of the trench to above the pad layer. The pad layer and portions of the epitaxial layer are removed (e.g., by chemical mechanical polishing), resulting in a planarized top surface of the epitaxial layer that is about coplanar with a top surface of the silicon layer. Electronic devices may be formed within the epitaxial silicon of the trench. Such electronic devices may include dynamic random access memory (DRAM), bipolar transistors, Complementary Metal Oxide Semiconductor (CMOS) circuits which are sensitive to floating body effects, and devices requiring threshold voltage matching. Semiconductor devices (e.g., field effect transistors) may be coupled to the SOI structure outside the trench.

SOI hybrid structure with selective epitaxial growth of silicon

A silicon on insulator (SOI) dynamic random access memory (DRAM) cell and array and method of manufacture. The memory cell includes a trench storage capacitor connected by a self aligned buried strap to a vertical access transistor. A buried oxide layer isolates an SOI layer from a silicon substrate. The trench capacitor is formed in the substrate and the access transistor is formed on a sidewall of the SOI layer. A polysilicon strap connected to the polysilicon plate of the storage capacitor provides a self-aligned contact to the source of the access transistor. Initially, the buried oxide layer is formed in the wafer. Deep trenches are etched, initially just through the SOI layer and the BOX layer. Protective sidewalls are formed in the trenches. Then, the deep trenches are etched into the substrate. The volume in the substrate is expanded to form a bottle shaped trench. A polysilicon capacitor plate is formed in the deep trenches and conductive polysilicon straps are formed in the trenches between the capacitor plates and the SOI sidewalls. Device regions are defined in the wafer and a sidewall gate is formed in the deep trenches. Shallow trenches isolation (STI) is used to isolate and define cells. Bitlines and wordlines are formed on the wafer.

Silicon-on-insulator vertical array device trench capacitor DRAM

Selective deposition of a refractory metal on a silicon substrate utilizing high temperature and a silane reduction process in which the flow rate ratio of silane to refractory metal halide gas is less than one. In a second embodiment, an additional layer of the refractory metal is deposited utilizing a hydrogen reduction of the metal halide gas at very high temperatures. In both embodiments, a refractory metal barrier layer may be provided by forming a self-aligned refractory metal silicide layer. Alternatively, a two layer self-aligned barrier is formed of a refractory metal silicide lower layer and a refractory metal nitride upper layer and the refractory metal is selectively deposited on the metal nitride.

Method for selective deposition of refractory metals on silicon substrates and device formed thereby

Demonstrating a >10X density increase over traditional VLSI fuse circuits, a compact eFUSE programmable array memory configured as a 4 Kb one-time programmable ROM (OTPROM) is presented using a 6.2 mum2 NiSix silicide electromigration ITIR cell in 65 nm SOI CMOS. A 20 mus programming time at 1.5 V is achieved by asymmetrical scaling of the fuse and a shared differential sensing scheme. Having zero process cost adder, eFUSE is fully compatible with standard VLSI manufacturing.

Dan Moy

Papers

Electrically Programmable Fuse (eFUSE): From Memory Redundancy to Autonomic Chips

SOI hybrid structure with selective epitaxial growth of silicon

Silicon-on-insulator vertical array device trench capacitor DRAM

Method for selective deposition of refractory metals on silicon substrates and device formed thereby

A Compact eFUSE Programmable Array Memory for SOI CMOS