Method of manufacturing semiconductor device having mask layer forming step for ion implantation
AssigneeKabushiki Kaisha Toshiba
InventorHidetoshi Koike
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Abstract
A gate oxide layer and a polysilicon layer are formed in sequence over the major surface of a semiconductor substrate. A photoresist layer is formed on the polysilicon layer and an opening is formed in the photoresist layer. Using the photoresist layer as a mask, boron is ion implanted through the polysilicon layer and the gate oxide layer into the semiconductor substrate. Phosphorus is next ion implanted into the polysilicon layer by using the photoresist layer as a mask. Different ion species are ion implanted into the semiconductor substrate and the polysilicon layer, respectively, by using the same photoresist layer, thus decreasing the number of photoetching steps in manufacture of semiconductor devices.
Claims35
A method of manufacturing a semiconductor device comprising the steps of:
- forming an oxide layer over the major surface of a semiconductor substrate;
- depositing a conductive layer over the entire surface;
- forming a mask layer which has an opening to expose a portion of said conductive layer;
- ion implanting first impurities into said semiconductor substrate through said conductive layer and said oxide layer using said mask layer as a mask;
- ion implanting second impurities into said conductive layer using said mask layer as a mask;
- and
- etching, after said mask layer is removed, said conductive layer so as to leave a portion, thereby forming a gate electrode.
A method of manufacturing a semiconductor device comprising the steps of:
- forming an oxide layer over the major surface of a semiconductor substrate;
- depositing a conductive layer over the entire surface of said oxide layer;
- etching said conductive layer so as to leave a portion which serves as a gate electrode;
- forming a mask layer which has an opening over said gate electrode and said oxide layer;
- ion implanting first impurities into said semiconductor substrate through said gate electrode and said oxide layer using said mask layer as a mask;
- and
- ion implanting second impurities into said gate electrode and said semiconductor substrate using said mask layer as a mask.
A method of manufacturing a semiconductor device comprising the steps of:
- forming an oxide layer over the major surface of a semiconductor substrate having a first and a second device region;
- depositing a conductive layer over the entire surface of said oxide layer;
- forming, over said conductive layer, a first mask layer having an opening located over said first device region in said semiconductor substrate;
- ion implanting first impurities into said semiconductor substrate through said conductive layer and said oxide layer using said first mask layer as a mask;
- ion implanting second impurities into said conductive layer using said first mask layer as a mask;
- forming, over said conductive layer, a second mask layer having an opening located over said second device region after said first mask layer is removed;
- ion implanting third impurities into said semiconductor substrate through said conductive layer and said oxide layer using said second mask layer as a mask;
- ion implanting fourth impurities into said conductive layer using said second mask layer as a mask;
- and
- etching, after said second mask layer is removed, said conductive layer so that first and second portions that are respectively located over said first and second device regions are left, thereby forming first and second gate electrodes over said first and second device regions, respectively.
A method of manufacturing a semiconductor device comprising the steps of:
- forming an oxide layer over the major surface of a semiconductor substrate having a first and a second device region;
- depositing a conductive layer over the entire surface of said oxide layer;
- etching said conductive layer so that first and second portions that are respectively located over said first and second device regions are left, thereby forming first and second gate electrodes over said first and second device regions, respectively;
- forming, over said conductive layer, a first mask layer having an opening located over said first device region in said semiconductor substrate;
- ion implanting first impurities into said semiconductor substrate through said first gate electrode and said oxide layer using said first mask layer as a mask;
- ion implanting second impurities into said first gate electrode and said semiconductor substrate using said first mask layer as a mask;
- forming, over said conductive layer, a second mask having an opening located over said second device region after said first mask layer is removed;
- ion implanting third impurities into said semiconductor substrate through said second gate electrode and said oxide layer using said second mask layer as a mask;
- and
- ion implanting fourth impurities into said second gate electrode and said semiconductor substrate using said second mask layer as a mask.
Dependencies are inferred from the claim text.