Semiconductor device and method of manufacturing the same
There are provided the steps of forming an insulating film over a semiconductor substrate, forming sequentially a first conductive film, a dielectric film, a second conductive film on the insulating film, etching the second conductive film and the dielectric film into a first pattern shape by using a first mask, removing the first mask, and etching simultaneously the first conductive film and the second conductive film having the first pattern shape by using a second mask to form a plurality of capacitor upper electrodes made of the second conductive film and also form a plate line as a capacitor lower electrode, which is covered with the dielectric film having the first pattern shape and has a contact region, made of the first conductive film. Accordingly, a plurality of capacitors can be formed on the capacitor lower electrode with good precision.
1. A semiconductor device comprising:
a first insulating film formed over a semiconductor substrate;
a capacitor lower electrode formed over the first insulating film to have a contact region;
capacitor upper electrodes formed over a region of the capacitor lower electrode except the contact region at an interval mutually;
a dielectric film formed between the capacitor lower electrode and the capacitor upper electrodes to cover the capacitor lower electrode in an area between the capacitor upper electrodes;
an electrically isolated conductive pattern formed around the contact region of the capacitor lower electrode and having a same layer structure as a conductive film constituting the capacitor upper electrodes;
wherein the isolated conductive pattern is formed in a region between the capacitor upper electrodes and the contact region of the capacitor lower electrode and has a rectangular shape to extend along the boundary between the dielectric film and the contact region of the capacitor lower electrode, and
wherein the dielectric film is formed continuously from an area under the isolated conductive pattern to areas under the capacitor upper electrodes.
2. A semiconductor device according to claim 1 , wherein the capacitor upper electrodes are formed over the capacitor lower electrode in two columns.
3. A semiconductor device according to claim 1 , wherein a capacitor protection insulating film is formed on each of upper surfaces of the capacitor upper electrodes, which has an almost same shape as the upper surfaces of the capacitor upper electrodes.
4. A semiconductor device according to claim 3 , wherein a protection insulating film having a same layer structure as the capacitor protection insulating film is formed around the contact area of the capacitor lower electrode.
5. A semiconductor device according to claim 1 , further comprising:
impurity diffusion regions formed on a surface region of the semiconductor substrate in regions on both sides of the capacitor lower electrode;
a second insulating film formed on the capacitor lower electrode, the capacitor upper electrodes, the dielectric film, and the first insulating film; and
wiring formed on the second insulating film to connect electrically one of the capacitor upper electrodes and one of the impurity diffusion regions by one to one.
6. A semiconductor device according to claim 5 , wherein the impurity diffusion regions constitute a transistor.