| 摘要 |
PURPOSE: A method for manufacturing trench transistor using trench side wall as channel layer is provided to obtain a semiconductor element with a high integration by forming a vertical type channel layer through using trench side walls. CONSTITUTION: A method comprises the steps of forming a thin trench onto a silicon substrate(30); depositing a nitride film at the bottom surface of the silicon substrate, and etching the resultant structure so as to form a trench spacer at the side wall of the trench; forming an element isolation film(33B) at the silicon substrate and the lower portion of the trench by using the trench spacer as a barrier film; forming a P-well by implanting P-type impurity ion to one side wall of the trench, and an N-well by implanting N-type impurity ion to the other side wall of the trench; forming a channel area by implanting impurity ion to side walls of the trench, respectively, where the P-well and N-well are formed; forming a gate oxide film(34) at the bottom surface of the silicon substrate including the trench, depositing a gate conductive film in such a manner as to cover the trench area, and partially etching the resultant structure so as to form a gate electrode(35); implanting a low concentration impurity ion to the trench side wall where the gate electrode is not formed, so as to form a low concentration source/drain area; forming a gate spacer(36) at the side surface of the gate electrode, and implanting a high concentration impurity ion to the resultant structure so as to form a high concentration source/drain area; and depositing an inter-layer insulation film onto the silicon substrate in such a manner as to cover the gate electrode, and forming a connection wire(38) contacting the gate electrode.
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