Nonvolatile semiconductor memory and method for fabricating the same
A nonvolatile semiconductor memory includes a first semiconductor layer; second semiconductor regions formed on the first semiconductor layer having device isolating regions extended in a column direction; a first interlayer insulator film formed above the first semiconductor layer; a lower conductive plug connected to the second semiconductor regions; a first interconnect extended in a row direction; a second interlayer insulator formed on the lower conductive plug and the first interlayer insulator film; an upper conductive plug; and a second interconnect formed on the second interlayer insulator contacting with the top of the upper conductive plug extended in the column direction.
1. A method for fabricating a nonvolatile semiconductor memory comprising:
forming a barrier insulator film on a semiconductor substrate;
subsequently forming a first interlayer insulator film on the barrier insulator film;
delineating a data transfer line contact and a source line contact in the first interlayer insulator film;
forming a trench in the first interlayer insulator film to bury a source line and a passing interconnect;
depositing a first barrier metal in the trench;
depositing a first metallic material to fill the trench;
etching back the first metallic material to form the data transfer line contact, the source line contact, a source line, and a passing interconnect in the first interlayer insulator film;
depositing a second interlayer insulator film on the first interlayer insulator film;
delineating for a via contact in second interlayer insulator film;
etching the second interlayer insulator film so as to extend the top of the data transfer line contact;
depositing a second barrier metal on the top of the data transfer line contact;
filling a second metallic material on the second barrier metal;
etching back the second metallic material; and
forming the via contact in second interlayer insulator film.
2. The method of claim 1 , wherein,
delineating for the data transfer line contact and the source line contact and etching the barrier insulator film are performed simultaneously.
3. The method of claim 1 , wherein,
delineating for the data transfer line contact and the source line contact, and etching the barrier insulator film are performed separately.
4. A method for fabricating a nonvolatile semiconductor memory, comprising:
forming a barrier insulator film on a semiconductor substrate;
subsequently forming a first interlayer insulator film on the barrier insulator film;
delineating a data transfer line contact and a source line contact simultaneously in the first interlayer insulator film;
forming a trench in the first interlayer insulator film to bury the data transfer line contact and the source line contact;
depositing and filling one of phosphorus or arsenic doped polycrystalline silicon in the trench;
etching back the doped polycrystalline silicon to bury the data transfer line contact and the source line contact in the first interlayer insulator film;
forming another trench in the first interlayer insulator film to bury a source line, a passing interconnect, and a data transfer line interconnect;
depositing a first barrier metal in the another trench;
depositing a first metallic material to fill the another trench;
etching back the first metallic material;
forming the source line, the passing interconnect, and the data transfer line interconnect filled in the first interlayer insulator film;
depositing a second interlayer insulator film on the first interlayer insulator film;
delineating for a via contact in the second interlayer insulator film;
etching the second interlayer insulator film so as to extend the top of the data transfer line interconnect;
depositing a second barrier metal on the top of the data transfer line interconnect;
filling the second metallic material on the second barrier metal;
etching back the second metallic material; and
forming the via contact in the second interlayer insulator film.