| 摘要 |
PURPOSE:To provide a steep and shallow NPN junction by implanting B ions into a semiconductor substrate subsequently after implanting As ions and making a part of substrate amorphous, without a heat treatment and annealing. CONSTITUTION:As ions are implanted through a thermal oxidation film on an N type Si substrate of <111> plane and a part of substrate is made amorphous. Subsequently, without annealing, B ions are implanted into the part which was made amorphous. At this time, a projection range of B ions is determined to be shallower than a distribution of As. The distribution 21 of B in a depth direction of an NPN junction transistor thus fabricated shows the extent 22 in a foot part of distribution which can be regarded as a channeling effect, but an inclination is steep and consequently a distribution of B in a base region 23 becomes steep. A width of base becomes narrow and a current amplification factor and the maximum operation frequency increase. |
