The conventional bus system architecture consists of masters, slaves, arbiter, decoder and so on in shared bus. As several masters can't use a bus concurrently, arbiter plays an role in arbitrating the bus. The efficiency of bus usage can be determined by the selection of arbitration method. Fixed Priority, Round-Robin, TDMA and Lottery arbitration policies are studied in the conventional arbitration method where the bus transaction cycle, the wait cycle and the priority are primarily considered. In this paper, we propose the arbitration method that considers the wait cycle. Furthermore, we verify the bus transaction cycle and the wait cycle compared with the other arbitration methods through TLM(Transaction Level Model).키워드 : 버스 중재, 버스, 대기 사이클, SoC

RuO x films were deposited by liquid delivery metalorganic chemical vapor deposition method using a new Ru(C8H13O2)3 precursor for the advanced capacitor electrode in Gbit-scale dynamic random access memory. Deposition was carried out on a TiN barrier layer in the range of 250–400°C and the ratio of the O2 flow rate to the total flow rate of Ar and O2 was varied from 20 to 80%. RuO x thin films were annealed at 650°C for 1 min with Ar, N2 or NH3 ambient. Film characterization was performed in terms of resistivity, crystal structure, surface morphology, microstructure and film purity. The resistivity depended on the impurity, grain density and crystalline structure of the film. The oxygen used to form Ru the oxide was found to eliminate the carbon and hydrogen elements in an organic source. The O2 flow ratio that changes the crystal structure of the films from Ru to RuO2 was found to be 40%. The metallic Ru phase forming a RuO2/Ru bilayer at the RuO2/TiN interface was observed at O2 flow ratios of 50% and 60%. The X-ray diffraction results indicate that the RuO2 phase and the silicidation are not observed regardless of the ambient gases. Ar was more effective than N2 and NH3 as an ambient gas for the postannealing of the Ru films.

Defect generation during organic bottom anti-reflective coating (BARC) in the photo lithography process is closely related to humidity control in the BARC coating unit. Defects are related to the water component due to the humidity and act as a blocking material for the etching process, resulting in an extreme pattern bridging in the subsequent BARC etching process of the poly etch step. In this paper, the lower limit for the humidity that should be stringently controlled for to prevent defect generation during BARC coating is proposed. Various images of defects are inspected using various inspection tools utilizing optical and electron beams. The mechanism for defect generation only in the specific BARC coating step is analyzed and explained. The BARC defect-induced gate pattern bridging mechanism in the lithography process is also well explained in this paper.

As the scaling trend becomes accelerated in process technology for cost reduction in semiconductor chip manufacturing, the requirement for shrink technology has increased. Hot Carrier Injection (HCI) degradation for I/O transistors is most concerning part when shrink. To solve this, the effective channel length (Leff) was increased using liner oxide before Light Doped Drain (LDD) implants and optimized the tilt angle to increase Leff without E-field degradation in LDD region, satisfying the HCI specification.

In this paper, a carbon implant is investigated in detail from the perspectives of performance advantages and side effects for the thick n-type metal-oxide-semiconductor field-effect transistor (n-MOSFET). Threshold voltage (Vth) adjustment using a carbon implant significantly improves the Vth mismatch performance in a thick (3.3-V) n-MOS transistor. It has been reported that a bad mismatch occurs particularly in the case of 0.11-μm Vth node technology. This paper investigates a carbon implant process as a promising candidate for the optimal Vth roll-off curve. The carbon implant makes the Vth roll-off curve perfectly flat, which is explained in detail. Further, the mechanism of hot carrier injection lifetime degradation by the carbon implant is investigated, and new process integration involving the addition of a nitrogen implant in the lightly doped drain process is offered as its solution. This paper presents the critical side effects, such as Isub increases and device performance shifts caused by the carbon implant and suggests an efficient method to avoid these issues.