Bipolar transistor formed by a high energy ion implantation method
AssigneeMitsubishi Denki Kabushiki Kaisha
InventorsAtsushi Kinoshita, Tomohisa Wada
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Abstract
In an NPN bipolar transistor having a special structure in which each impurity region is formed by ion implantation, a width of a base region is significantly reduced, and therefore, current amplification factor hfe is increased, resulting in improvement in performance thereof. Furthermore, a Bi-CMOS transistor can be manufactured using a CMOS process. The use of the bipolar transistor having a special structure for a driving circuit allows implementation of a driving circuit having large driving force with slight increase in cost.
Claims4
A method of manufacturing a semiconductor device, comprising the steps of:
- providing a semiconductor substrate of a first conductivity type having a main surface;
- forming first and second impurity regions of a second conductivity type spaced apart from each other at said main surface by ion implantation;
- forming a third impurity region of said first conductivity type between said first and second impurity regions of a second conductivity type at said main surface;
- forming first and second gate electrodes on respective main surfaces of said second impurity region and said third impurity region with an insulating film interposed therebetween;
- forming a fourth impurity region of said first conductivity type at the main surface of said second impurity region by ion implantation using said first gate electrode as a mask;
- forming a fifth impurity region of said second conductivity type at the main surface of said third impurity region by ion implantation using said second gate electrode as a mask;
- forming a sixth impurity region of a first conductivity type at a portion of the main surface of said first impurity region by ion implantation;
- and
- forming a seventh impurity region of a second conductivity type at a portion of a main surface of said sixth impurity region by ion implantation,
- whereby a bipolar transistor is constituted by said sixth impurity region, said seventh impurity region, and said first impurity region.
Dependencies are inferred from the claim text.