Masafumi Watari

MD-SCAN method for low power scan testing

As semiconductor manufacturing technology advances, power dissipation and noise in scan testing have become critical problems. Our studies on practical LSI manufacturing show that power supply voltage drop causes testing problems during shift operations in scan testing. In this paper, we present a new testing method named MD-SCAN (multi duty-scan) which solves power supply voltage drop problems, as well as its experimental results applied to practical LSI chips.

Preparation and characteristics of the TlBr‐TlI fiber for a high power CO2 laser beam

The TlBr‐TlI (thallium bromoiodide) crystal and its fiber preparation method were studied in order to develop a high power CO2 laser beam fiber. As a result of this study, the most preferable composition for the fiber was determined to be 42 wt. % TlBr. The fiber (0.5 mm in diameter and 1.5 m in length) at that composition had the following excellent characteristics: (1) a high output power of 138 W (70 kW/cm2), (2) a high total transmissivity of more than 93%/1.5 m, and (3) a bending radius of ultimate 3.5 cm.

Practical application of automated fault diagnosis for stuck-at, bridging, and measurement condition dependent faults in fully scanned sequential circuits

A practical fault diagnosis system based on combination automatic test pattern generation (ATPG) and fault simulation is described. Our fault diagnosis system deals with conventional stuck-at and bridging faults, as well as measurement condition dependent (MCD) faults in order to diagnose those faults causing different behavior with measurement condition such as supply voltage and temperature, using single stuck-at based diagnosis techniques. Experimental results with a practical very deep submicron (VDSM) LSI circuit shows that a defective chip can be efficiently diagnosed using our diagnostic algorithm and newly proposed MCD fault model.