MRAM integration with low-K inter-metal dielectric for reduced parasitic capacitance
Systems and methods of integration of resistive memory elements with logic elements in advanced nodes with improved mechanical stability and reduced parasitic capacitance include a resistive memory element and a logic element formed in a common integration layer extending between a bottom cap layer and a top cap layer. At least a first intermetal dielectric (IMD) layer of high-K value is formed in the common integration layer and surrounding at least the resistive memory element, to provide high rigidity and mechanical stability. A second IMD layer of low-K value to reduce parasitic capacitance of the logic element is formed in either the common integration layer, a top layer above the top cap layer or an intermediate layer in between the top and bottom cap layers. Air gaps may be formed in one or more IMD layers to further reduce capacitance.
1. A method of forming a semiconductor device, the method comprising:
forming first and second vias for a logic element and a resistive memory element, respectively, in an intermediate intermetal dielectric (IMD) layer of low-K value;
forming the logic element and the resistive memory element in a first IMD layer of high-K value, wherein the first IMD layer is formed above the intermediate IMD layer, and wherein a combination of the intermediate IMD layer and the first IMD layer extends between a bottom cap layer and a top cap layer; and
forming at least one air gap in the combination of the intermediate IMD layer and the first IMD layer, with at least a portion of the at least one air gap in each of the intermediate IMD layer and the first IMD layer.
2. The method of claim 1 , comprising forming the logic element as a metal line using a single damascene process.
3. The method of claim 1 , comprising forming the first and second vias from a single damascene process.
4. The method of claim 1 , further comprising forming a top IMD layer of low-K value on top of the top cap layer, and forming top metal line contacts to the logic element and the resistive memory element in the top IMD layer.
5. The method of claim 4 , comprising forming the top metal line contacts from a dual damascene process.
6. The method of claim 1 , further comprising forming bottom metal line contacts in a bottom IMD layer below the bottom cap layer.
7. A semiconductor device comprising:
first and second vias for a logic element and a resistive memory element formed in an intermediate intermetal dielectric (IMD) layer of low-K value,
wherein the logic element and the resistive memory element are formed in a first IMD layer of high-K value, wherein the first IMD layer is formed above the intermediate IMD layer, and
wherein a combination of the intermediate IMD layer and the first IMD layer extend between a bottom cap layer and a top cap layer; and
at least one air gap formed in the combination of the intermediate IMD layer and the first IMD layer, with at least a portion of the at least one air gap in each of the intermediate IMD layer and the first IMD layer.
8. The semiconductor device of claim 7 , wherein the logic element comprises a metal line formed from a single damascene process.
9. The semiconductor device of claim 7 , further comprising a top IMD layer of low-K value on top of the top cap layer, and top metal line contacts to the logic element and the resistive memory element in the top IMD layer.
10. The semiconductor device of claim 7 , further comprising bottom metal line contacts in a bottom IMD layer below the bottom cap layer.
11. The semiconductor device of claim 7 integrated in a device, selected from the group consisting of a set top box, music player, video player, entertainment unit, navigation device, communications device, personal digital assistant (PDA), fixed location data unit, and a computer.
12. The semiconductor device of claim 7 , integrated in at least one semiconductor die.