Semiconductor device and method for manufacturing same
View Patent ↗A semiconductor device is provided which has a capacitor insulating film made up of zirconium aliminate being an amorphous film obtained by having crystalline dielectric contain amorphous aluminum oxide and having its composition of Al X Zr (1-X) O Y (0.05≦X≦0.3), hereby being capable of preventing, in a process of forming a capacitor of MIM (Metal Insulator Metal) structure, dielectric breakdown of a capacitor insulating film while a relative dielectric constant of a metal oxide film used as the capacitor insulating film is kept high.
1. A method for manufacturing a semiconductor device comprising a capacitor of MIM (Metal Insulator Metal) structure comprising a lower electrode and an upper electrode each made up of a metal film, and a capacitor insulating film sandwiched between said lower electrode and said upper electrode, the method comprising:
forming said lower electrode;
forming said capacitor insulating film on said lower electrode, said capacitor insulating film comprising an amorphous dielectric film having a composition of Al X Zr (1-X) Oy by a first compound containing metal atoms having a tendency to form a crystalline dielectric, an oxidizing agent, and a second compound containing aluminum atoms; and
forming said upper electrode on said capacitor insulating film, thereby forming said capacitor of said MIM structure.
2. The method for manufacturing the semiconductor device according to claim 1 wherein, in the compostion of said Al X Zr (1-X) Oy, a range of “X” is set to be 0.05≦X≦0.3.
3. The method for manufacturing the semiconductor device according to claim 1 , wherein, in the capacitor insulating film forming process, said semiconductor substrate is exposed in atmosphere into which each of said first compound containing metal atoms being able to form crystalline dielectric, said oxidizing agent, and said second compound containing aluminum atoms is fed with different timing.
4. The method for manufacturing the semiconductor device according to claim 3 , wherein, when a combination of a period during which said first compound containing metal atoms being able to form said crystalline dielectric is fed and a period during which said oxidizing agent is subsequently fed is defined to be a unit operation cycle, by repeating said unit operation cycle, said crystalline dielectric is formed so as to have a desired thickness.
5. The method for manufacturing the semiconductor device according to claim 4 , wherein, when said crystalline dielectric is formed by repeating said unit operation cycle, control is exerted so that a film thickness of said crystalline dielectric to be formed every unit operation cycle is about 4 nm or less.
6. The method for manufacturing the semiconductor device according to claim 3 , when a combination of a period during which said second compound containing aluminum atoms is fed and a period during which said oxidizing agent is subsequently fed is defined to be a unit operation cycle, by repeating said unit operation cycle, said amorphous aluminum oxide film is formed so as to have a desired thickness.
7. The method for manufacturing the semiconductor device according to claim 1 , wherein, in the capacitor insulating film forming process, said semiconductor substrate is exposed in atmosphere into which each of first compound containing metal atoms being able to form said crystalline dielectric, said oxidizing agent, and said second compound containing aluminum atoms is fed with same timing.
8. The method for manufacturing the semiconductor device according to claim 1 , wherein, as a metal being able to form said crystalline dielectric, zirconium, hafnium, or lanthanoid group element is used.
9. The method for manufacturing the semiconductor device according to claim 1 , wherein, as said upper electrode and said lower electrode, titanium nitride, tantalum nitride, or tungsten nitride is used.