Method of manufacturing semiconductor device
View Patent ↗A method of manufacturing a semiconductor device includes providing a semiconductor substrate on which a plurality of transistors are defined; forming a wiring pattern over the transistors, the wiring pattern contacting at least one transistor; depositing a first oxide film over the wiring pattern; defining a first contact hole on the oxide film, the first contacting hole exposing the wiring pattern; forming a lower metal layer having a first barrier metal layer, a first metal layer and a second barrier metal layer over the oxide film, the lower metal layer filling the first contact hole; forming a contact hole stop conduction layer over the lower metal layer; depositing a second oxide film over the contact hole stop conduction layer; etching a selected portion of the second oxide film to form a hole exposing the contact hole stop conduction layer; etching the exposed contact hole stop layer to define a second contact hole; forming a contact plug within the second contact hole, the contact plug contacting the lower metal layer; and forming an upper metal layer including a third barrier metal layer and a second metal layer, the upper metal layer contacting the contact plug.
1. A method of manufacturing a semiconductor device, the method comprising:
providing a semiconductor substrate on which a plurality of transistors has been defined;
forming a wiring pattern over the transistors, the wiring pattern being coupled to at least one transistor;
depositing an Inter Layer Dielectric (ILD) film over the wiring pattern;
defining a first contact hole in the ILD film, the first contact hole exposing a portion of the wiring pattern;
forming a lower metal layer including a first barrier metal layer, a first metal layer, and a second barrier metal layer, the lower metal layer contacting the wiring pattern via the first contact hole;
forming a contact hole stop conduction layer over the lower metal layer;
patterning the contact hole stop conduction layer and the lower metal layer to define one or more through-holes;
depositing an Inter Metal Dielectric (IMD) film over the contact hole stop conduction layer, the IMD film filling the one or more through-holes;
etching a selected portion of the IMD film using a first etch step, the first etch stop substantially exposing the contact hole stop conduction layer and removing a portion of the contact hole stop conduction layer, thereby providing the contact hole stop conduction layer with a reduced thickness;
etching the contact hole stop conduction layer of the reduced thickness using a second etch step until the second barrier metal layer is exposed, so that a second contact hole is defined;
forming a contact plug within the second contact hole, the contact plug contacting an upper surface of the lower metal layer; and
forming an upper metal layer over the contact plug and the IMD film, the upper metal layer contacting an upper surface of the contact plug.
2. The method of claim 1 , wherein the first etch step uses an etch gas that has high selectivity to the contact hole stop conduction layer.
3. The method of claim 1 , wherein the contact hole stop conduction layer comprises conductive material.
4. The method of claim 3 , wherein the contact hole stop conduction layer comprises tungsten (W), platinum (Pt), ruthenium (Ru), iridium (Ir) and copper (Cu).
5. The method of claim 1 , wherein the contact hole stop conduction layer is formed on the lower metal layer to a thickness of 10 Å to 3000 Å.
6. The method of claim 1 , wherein the second etch step involves a Radio Frequency (RF) sputtering process to remove the contact hole stop conduction layer remaining over the lower metal layer, the method further comprising:
after the second etch step, depositing in-situ a contact plug metal layer on the IMD film to fill the second contact hole; and
polishing the contact plug metal layer using the IMD film as a stop layer to form the contact plug.
7. The method of claim 6 , wherein in the step of forming the contact hole stop conduction layer, a thickness of the etch stop layer formed over the lower metal layer is determined by a thickness of the contact hole stop conduction layer remaining over the lower metal layer after the first etch step and a thickness of the contact hole stop conduction layer etched by the second etch step.
8. The method of claim 1 , wherein the first etch step is a plasma etch process employing C x H y F z gas.
9. A method of manufacturing a semiconductor device, the method comprising:
providing a semiconductor substrate on which a plurality of transistors are defined;
forming a wiring pattern over the transistors, the wiring pattern contacting at least one transistor;
depositing a first oxide film over the wiring pattern;
defining a first contact hole on the oxide film, the first contacting hole exposing the wiring pattern;
forming a lower metal layer having a first barrier metal layer, a first metal layer and a second barrier metal layer over the oxide film, the lower metal layer filling the first contact hole;
forming a contact hole stop conduction layer over the lower metal layer;
depositing a second oxide film over the etch stop layer;
etching a selected portion of the second oxide film to form a hole exposing the contact hole stop conduction layer;
etching the exposed contact hole stop conduction layer to define a second contact hole;
forming a contact plug within the second contact hole, the contact plug contacting the lower metal layer; and
forming an upper metal layer including a third barrier metal layer and a second metal layer, the upper metal layer contacting the contact plug.
10. The method of claim 9 , wherein the contact hole stop conduction layer comprises tungsten (W), platinum (Pt), ruthenium (Ru), iridium (Ir) and copper (Cu).
11. The method of claim 9 , wherein the contact hole stop conduction layer is formed to a thickness of 10 Å to 3000 Å.
12. The method of claim 9 , wherein the exposed contact hole stop conduction layer is etched using a RF sputtering process, wherein the contact plug is formed by depositing in-situ a contact plug metal layer into the second contact hole after the RF sputtering process.
13. The method of claim 12 , wherein the contact plug metal layer is removed using a chemical mechanical polishing step to form the contact plug, the second oxide film being used as a stop layer.
14. The method of claim 7 , wherein the selected portion of the second oxide film is etched using C x H y F z gas.
15. A method of manufacturing a semiconductor device, the method comprising:
providing a semiconductor substrate on which a plurality of transistors have been defined;
forming a wiring pattern over the transistors, the wiring pattern being coupled to at least one transistor;
depositing an Inter Layer Dielectric (ILD) film over the wiring pattern;
defining a first contact hole in the ILD film, the first contact hole exposing a portion of the wiring pattern;
forming a lower metal layer including a first barrier metal layer, a first metal layer, and a second barrier metal layer, the lower metal layer contacting the wiring pattern via the first contact hole;
forming a contact hole stop conduction layer over the lower metal layer;
patterning the contact hole stop conduction layer and the lower metal layer to define one or more through-holes;
depositing an Inter Metal Dielectric (IMD) film over the contact hole stop conduction layer, the IMD film filling the one or more through-holes;
etching a selected portion of the IMD film using a first etch step at least until the contact hole stop conduction layer is substantially exposed;
etching the exposed contact hole stop conduction layer using a second etch step until the second barrier metal layer is exposed, so that a second contact hole is defined;
forming a contact plug within the second contact hole, the contact plug contacting an upper surface of the lower metal layer; and
forming an upper metal layer over the contact plug and the IMD film, the upper metal layer contacting an upper surface of the contact plug.