Method of manufacturing semiconductor device

摘要

A performance of a semiconductor device is improved. A film, which is made of silicon, is formed in a resistance element formation region on a semiconductor substrate, and an impurity, which is at least one type of elements selected from a group including a group 14 element and a group 18 element, is ion-implanted into the film, and a film portion which is formed of the film of a portion into which the impurity is ion-implanted is formed. Next, an insulating film with a charge storage portion therein is formed in a memory formation region on the semiconductor substrate, and a conductive film is formed on the insulating film.

主权项

1. A method of manufacturing a semiconductor device comprising steps of:
(a) preparing a semiconductor substrate; (b) forming a first insulating film in a first region of a main surface of the semiconductor substrate on the main surface of the semiconductor substrate; (c) forming a second insulating film in a second region of the main surface of the semiconductor substrate on the main surface of the semiconductor substrate; (d) forming a first film, which is made of silicon, on the first insulating film and the second insulating film; (e) ion-implanting a first impurity of a first conductivity type into the first film of the portion formed on the second insulating film to form a first conductive film which is formed of the first film of a portion into which the first impurity is ion-implanted; (f) ion-implanting a second impurity into the first film of a portion formed on the first insulating film to form a first film portion which is formed of the first film of a portion into which the second impurity is ion-implanted; (g) after the step of (f), forming a third insulating film with a charge storage portion therein in a third region of the main surface of the semiconductor substrate on the main surface of the semiconductor substrate; (h) forming a second conductive film on the third insulating film; (i) patterning the second conductive film to forma first gate electrode, which is formed of the second conductive film, and to form a first gate insulating film which is formed of the third insulating film of a portion between the first gate electrode and the semiconductor substrate; (j) patterning the first film portion to form a resistor body which is formed of the first film portion; and (k) patterning the first conductive film to form a second gate electrode, which is formed of the first conductive film, and to form a second gate insulating film which is formed of the second insulating film of a portion between the second gate electrode and the semiconductor substrate, wherein, in the step of (a), the semiconductor substrate having a first semiconductor region of a second conductivity type, formed on the main surface side of the semiconductor substrate in the second region, is prepared, the method of manufacturing the semiconductor device further comprising a step of: (l) forming a second semiconductor region of a third conductivity type, which is opposite to the second conductivity type, in an upper layer portion of the first semiconductor region of a portion adjacent to the second gate electrode when seen in a plan view, wherein the step of (g) includes steps of:
(g1) depositing the third insulating film in the third region on the main surface of the semiconductor substrate; and(g2) performing heat treatment on the semiconductor substrate, the step of (l) includes steps of:
(l1) ion-implanting a third impurity of the third conductivity type into the upper layer portion of the first semiconductor region of the portion adjacent to the second gate electrode when seen in a plan view; and(l2) after the step of (l1), performing heat treatment on the semiconductor substrate, the second impurity is at least one type of elements which is selected from a group including a group 14 element and a group 18 element, and a temperature of the heat treatment in the step of (g2) is higher than a temperature of the heat treatment in the step of (l2).