| 摘要 |
<p>PURPOSE:To enhance high temp. stability, by using polycrystalline silicon doped with boron as a heat generator and setting the concn. of boron to specific value or more and suppressing the concn. of oxygen in the heat generator to a specific value or less. CONSTITUTION:The heat generation part of a thermal head consists of a substrate 5 composed of alumina, a heat accumulating glaze layer 4, a heat generator 3, lead electrodes 2, 2' made of aluminum and an abrasion-resistant protective layer 1 composed of Si-B-N in succession from below. As the heat generator 3, polysilicon doped with boron is used and the doping amount of boron is st to 5X10<20>/cm<3> or more to reduce a change in sheet resistance. Since there is such a case that only a high temp. characteristic inferior to an expected one is obtained occasionally, the concn. of oxygen in boron doped polysilicon is set to 5X10<20>(atom/cm<3>) or less. By this method, a sheet resistance change rate is suppressed to 5% or less.</p> |
