Ichiro Nakayama

New doping method for subhalf micron trench sidewalls by using an electron cyclotron resonance plasma

A new doping method for the vertical sidewall of a trench by electron cyclotron resonance plasma is described. The plasma was produced under a pressure of 5×10−4 Torr. A doped layer was formed uniformly along the sidewall of a trench with subhalf micron width and an aspect ratio of 6.2. By using a de‐ionized water cooling system, the wafer temperature was maintained below 120 °C and the boron dopant was introduced without damage to the photoresist.

Development of a transparent and ultrahydrophobic glass plate

A transparent glass plate was roughened at the submicron level, and then a chemically adsorbed monolayer of a fluorocarbon compound was formed along the glass surface. The monolayer was prepared using the chemical coupling reaction accompanying dehydrochlorination between a chlorosilyl group of the heptadeca-fluorodecyltrichlorosilane (CF3(CF2)7(CH2)2SiCl3: HFTS) surface-active agent and a hydroxyl group on the glass surface. The contact angle of the glass surface relative to water was approximately 155 degrees with transmittance kept at 92%. This glass plate may be useful for various products, such as motor vehicles and building window glass.

New inductively coupled plasma source using a multispiral coil

The authors have developed a new inductively coupled plasma source (ICPS), using a multispiral coil with 1/3 the inductance of the conventional ICPS coil. This source can produce plasma of 1011 cm−3 or higher density with ±5% fluctuation, at pressures below 10 mTorr.