| 摘要 |
PURPOSE:To realize interelement isolation closer to perfect by a method wherein a groove for interelement isolation is etched in a semiconductor substrate by means of reactive ion beams produced with a gas plasma containing B by using a resist pattern on the substrate as a mask. CONSTITUTION:The resist pattern 22 is formed on the Si substrate 21 by the photo engaving technique. Next, the reactive ion beam 24 is produced with a gas plasma containing a B-containing gas such as BF3, BCl3, BBr3, or BI3. The groove 23 is etched in the Si substrate 21 by RIE with this reactive ion beam 24: the beam 24 containing B is partly injected to the bottom and the side surface of the groove 23 at the same time with the formation of this groove 23; therefore, a B-injected region 25 is automatically formed over the inner wall of the groove 23 at the time of etching end. Accordingly, optimum heat treatments thereafter enable a B high concentration region to be formed over the wall of the groove 23 by using the region 25 as the diffusion source, resulting in the perfection of electrical insulation in the direction along the side wall. |
