Method for fabricating capacitor in semiconductor device
View Patent ↗Disclosed is a method of fabricating a capacitor of a semiconductor device, which can produce an MIM capacitor in which an insulator film is formed to have a positive slope by means of a polymer, thereby preventing leakage of current in the capacitor. The method comprises the steps of: sequentially forming a first metal film, an insulator film, and a second metal film on a semiconductor substrate; patterning a second metal film to form an upper electrode; etching the insulator film using the upper electrode as a mask, and simultaneously forming a polymer at one side of the upper electrode; etching the insulator film which is not protected by the polymer, thereby removing the insulator film; and removing the polymer formed at said one side of the upper electrode.
1. A method of fabricating a capacitor of a semiconductor device, the capacitor having a structure of metal-insulator-metal, the method comprising the steps of:
sequentially forming a first metal film, an insulator film, and a second metal film on a semiconductor substrate;
patterning a second metal film to form an upper electrode;
etching the insulator film using the upper electrode as a mask, and simultaneously forming a polymer at one side of the upper electrode;
etching the insulator film which is not protected by the polymer, thereby removing the insulator film; and
removing the polymer formed at said one side of the upper electrode.
2. A method of fabricating a capacitor of a semiconductor device according to claim 1 , wherein the first metal film is dry-etched by a plasma activated by combination of Cl 2 /BCL 3 /N 2 gas.
3. A method of fabricating a capacitor of a semiconductor device according to claim 1 , wherein a positive slope having a single inclination is formed at a boundary between the insulator film and the polymer.
4. A method of fabricating a capacitor of a semiconductor device according to claim 1 , wherein a positive slope having multiple inclinations is formed at a boundary between the insulator film and the polymer.
5. A method of fabricating a capacitor of a semiconductor device according to claim 1 , wherein the polymer is formed using CHF 3 and CF 4 gas with a high pressure and source powers of middle level and lower levels are used, and the CHF 3 gas is used with a similar or higher percentage than that of the CF 4 gas.
6. A method of fabricating a capacitor of a semiconductor device according to claim 5 , wherein the polymer is formed using C X F Y gas instead of CHF 3 and CF 4 gas.
7. A method of fabricating a capacitor of a semiconductor device according to claim 1 , further comprising the steps of:
forming interlayer insulator film on an entire surface of a first resultant lamination formed through above steps;
forming at least two via holes by etching the interlayer insulator film;
forming contact plugs by filling conductive metal in the via holes; and
forming at least two upper metal wiring films on a second resultant lamination formed through above steps.