Casting Manipulation—Midair Control of a Gripper by Impulsive Force

We have developed a casting manipulator that includes a flexible light string in the link mechanism to enlarge the workspace of the manipulator. In the casting manipulation, an end-effector is launched to its target by releasing the string connected to it, and its trajectory is controlled by the tension of the string. In this paper, we present the midair control of the end-effector. As a simple way, we propose the braking technique to apply impulsive force to the end-effector by braking the movement of the string. Examining dynamic characteristics of the string when an impulsive force applies to it, we show that the midair motion of the end-effector can be controlled by the braking technique. Then, we apply the braking technique to the multiple braking control of the trajectory. We confirm the effectiveness of the proposed method through simulations and experiments using casting manipulator hardware.     

Characteristics of PZT films with SRO/Pt stack electrodes for high density mbit feram devices

Abstract

Reliable PZT capacitors have been developed by using stable PZT sputtering technique and Pt/thinSRO(SrRuO₃) stack electrodes. Introduction of SRO electrodes with no leakage current degradation is a key to realize reliable and scalable PZT capacitors. Roles of top electrode (TE) SRO and bottom electrode (BE) SRO were investigated respectively from reliability and process damage points of view. The SRO works as hydrogen resistant electrodes, fatigue free interfaces and nucleation sites for perovskite formation. Relationship between SRO crystallinity and PZT electrical properties was elucidated. Templates made of thin SRO were found to function as barrier layers against diffusion of Pb and Ru from BE resulting in new possible cell structures.     

Suppression of the floating-body effect in partially-depleted SOIMOSFETs with SiGe source structure and its mechanism

SiGe layers were formed in source regions of partially-depleted 0.25-μm SOI MOSFETs by Ge implantation, and the floating-body effect was investigated for this SiGe source structure. It is found that the increase of the Ge implantation dosage suppresses kinks in I_d-V_d characteristics and that the kinks disappear for devices with a Ge dose of 3×10¹⁶ cm^-2. The lowering of the drain breakdown voltage and the anomalous decrease of the subthreshold swing are also suppressed with this structure. It is confirmed that this suppression effect originates from the decrease of the current gain for source/channel/drain lateral bipolar transistors (LBJTs) with the SiGe source structure. The temperature dependence of the base current indicates that the decrease of the current gain is ascribed to the bandgap narrowing of the source region     

Suppression of the floating-body effect in SOI MOSFET's by thebandgap engineering method using a Si1-xGex sourcestructure

The bandgap engineering method using a SiGe source structure is presented as a means to suppress the floating-body effect in SOI MOSFET's. Experiments using Ge implantation are carried out to form a narrow-bandgapped SiGe layer in the source region. It has been confirmed that Ge-implanted SIMOX exhibited a 0.1 eV bandgap narrowing with a relatively low Ge-dosage of 10¹⁶ cm^-2. The fabricated N-type SOI-MOSFET's exhibited suppressed parasitic bipolar effects, such as improvement of the drain breakdown voltage or latch voltage, and suppression of abnormal subthreshold slope. Advantages over other conventional methods are also discussed, indicating that the bandgap engineering provides a practical method to suppress the floating-body effect     

Characteristics of an Oxygen Barrier Based on Bi-layered Ir

For high-density ferroelectric random access memory devices (FeRAMs) with capacitor over plug (COP) structure, oxygen diffusion barriers based on bi-layered Ir have been investigated. This paper describes the detailed characteristics of the barriers. A bi-layered Ir barrier was fabricated by repeating the deposition and RTO treatment of an Ir metal film, which was very effective to obtain excellent barrier properties against oxygen diffusion. Surface roughening was shown after RTO, but can be suppressed by lowering the RTO temperature. The roughening is caused by the formation of a gaseous phase of IrOx during RTO, and not by the formation of Ir hillocks. The stress of the bi-layered Ir barrier is tensile after RTO, which makes further stacking of more layers on the barrier with good adhesion possible. Performance of this barrier was checked using the post annealing in ¹⁸O isotope ambient at 650°C for 2 hours. SIMS profile showed the barrier prevented the diffusion of ¹⁸O, effectively. The above results strongly suggest that the bi-layered Ir barrier can be applied to the COP structure for high-density FeRAMs.