Scratch protection for direct contact sensors
First Claim
1. An integrated circuit structure, comprising:
- a capacitive electrode;
a dielectric underlying the capacitive electrode; and
an active region underlying the dielectric, wherein the capacitive electrode and each conductive region between the capacitive electrode and the active region are formed of a conductive material having a hardness greater than a hardness of aluminum.
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Accused Products
Abstract
In capacitive sensor circuits where physical contact is required and excess pressure may be inadvertently applied to the sensor surface, aluminum is not sufficiently hard to provide “scratch” protection and may delaminate, causing circuit failure, even if passivation integrity remains intact. Because hard passivation layers alone provide insufficient scratch resistance, at least the capacitive electrodes and preferably all metallization levels within the sensor circuit in the region of the capacitive electrodes between the surface and the active regions of the substrate are formed of a conductive material having a hardness greater than that of aluminum. The selected conductive material preferably has a hardness which is at least as great as the lowest hardness for any interlevel dielectric or passivation material employed. The selected conductive material is employed for each metallization level between the surface and the active regions, including contacts and vias, landing pads, interconnects, capacitive electrodes, and electrostatic discharge protection lines. Tungsten is a suitable conductive material, for which existing processes may be substituted in place of aluminum metallization processes.
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Citations
27 Claims
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1. An integrated circuit structure, comprising:
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a capacitive electrode;
a dielectric underlying the capacitive electrode; and
an active region underlying the dielectric, wherein the capacitive electrode and each conductive region between the capacitive electrode and the active region are formed of a conductive material having a hardness greater than a hardness of aluminum. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. An integrated circuit structure, comprising:
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an active region;
a dielectric overlying the active region and having a contact opening therethrough;
a tungsten contact within the contact opening;
a tungsten metal region overlying the contact and a portion of the dielectric;
an interlevel dielectric overlying the tungsten metal region and the dielectric and having an opening therethrough;
a tungsten via within the opening through the interlevel dielectric; and
a tungsten capacitive electrode overlying the tungsten via and a portion of the interlevel dielectric, wherein the capacitive electrode is electrically connected to the active region by the contact, the metal region, and the via. - View Dependent Claims (10)
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11. An integrated circuit, comprising:
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an array of capacitive electrodes in a central portion of the integrated circuit; and
ESD protection devices and contact pads around a periphery of the integrated circuit, wherein the capacitive electrodes and every metallization region beneath the array of capacitive electrodes within the central portion of the integrated circuit is formed of a material having a hardness greater than aluminum while at least one metallization region beneath an ESP protection device or contact pad is formed of aluminum. - View Dependent Claims (12, 13, 15, 16, 17, 18, 19, 20, 21)
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14. A method of forming a scratch resistant integrated circuit structure, comprising:
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forming an active region;
forming a dielectric overlying the active region; and
forming a capacitive electrode overlying the dielectric, wherein the capacitive electrode and each conductive region between the capacitive electrode and the active region are formed of a conductive material having a hardness greater than a hardness of aluminum.
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22. A method of forming an integrated circuit structure, comprising:
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forming an active region;
forming a dielectric overlying the active region and having a contact opening therethrough;
forming a tungsten contact within the contact opening;
forming a tungsten metal region overlying the contact and a portion of the dielectric;
forming an interlevel dielectric overlying the tungsten metal region and the dielectric and having an opening therethrough;
forming a tungsten via-within the opening through the interlevel dielectric; and
forming a tungsten capacitive electrode overlying the tungsten via and a portion of the interlevel dielectric, wherein the capacitive electrode is electrically connected to the active region by the contact, the metal region, and the via. - View Dependent Claims (23, 25, 26, 27)
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24. A method of forming a scratch resistant integrated circuit structure, comprising:
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forming a plurality of active regions;
forming a dielectric over the plurality active regions; and
forming an array of capacitive electrodes overlying the dielectric of a conductive material having a hardness at least as great as a hardness of the dielectric.
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Specification