Sub-µm polysilicon super thin film transistor

Abstract

The application of poly Si super thin film transistors to VLSI technology, in which the active layer poly Si is 200-5OOA thick, has been investigated. The average grain size,of poly Si increased to more than lpm from 200-300A by solid phase recrystallization. Sub-um poly Si super thin film transistors and 19-stage CMOS ring oscillators were fabricated on 5inch insulator substrates. The mobility was about 100cm'/V.s for an N-channel and about 80cm2/V's for a P-channel transistor. The leakage current of transistors was O.lpA/um. The threshold voltage was 0.8V for an N-channel and -0.8V for a P-channel transistor, respectively. ,150~s of the delay time per stage and 0.15pJlgate 'of power-delay product at VDD=5V were obtained in the ring oscillator.

Thermodynamic Modeling of Arsenic in Copper Smelting Processes

“…The available data on As distribution between the matte and the slag from several commercial bath smelting [38,41,42] and flash smelting [43] processes are presented in Figure 6 as a function of matte grade. The scatter in each set of plant data includes some variations in the process variables that affect As partitioning and possible errors or uncertainties in the determination of low levels of As in the matte or the slag.…”

“…The calcium-ferrite-based slag has been used commercially in the Mitsubishi copperconverting process. [38] The distribution of As between the matte and the calcium ferrite slags at 1523 K (1250°C) under 0.1 atm SO 2 first was investigated by Acuna and Yazawa. [39] Roghani et al [40] also reported the distribution ratio of As between the calcium ferrite slag and the copper matte at 1523 K (1250°C) under varied SO 2 partial pressures.…”

“…The copper smelting processes can be classified into steady-state/continuous processes (e.g., Mitsubishi and Isasmelt bath smelters [38,42] and Outokumpo flash smelter [43] ) and batch-type processes (e.g., Peirce-Smith converter). [44] In the continuous processes, the feed materials are charged continuously and smelted with molten products being tapped on a semicontinuous basis while the reacted gases leave the reactor continuously.…”

“…According to Figure 6, the distribution of As between the slag and the matte in the smelting stage of the Mitsubishi process is slightly lower than that in the Noranda, Outokumpo, and Isasmelt processes. [38,[41][42][43] One key reason for this difference is the slag chemistry. The data on the Mitsubishi smelting process show that the slag is close to silica saturation, whereas the slags of the Noranda, Outokumpo, and Isasmelt processes contain about 25 wt pct SiO 2 .…”

“…Figure 7 ) with published data from plant measurements. [38,[41][42][43] The calculated equilibrium distribution ratio were for slags with an Fe/SiO 2 ratio of 2.2 at 1523 K (1250°C) and P SO2 of 0.2 atm. .…”