Scratch resistance improvement by filling metal gaps
AssigneeSTMicroelectronics S.r.l.
InventorsDanielle A. Thomas, Harry Michael Siegel
Life of this patent
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Abstract
Passivation for capacitive sensor circuits, which overlies the capacitive sensor electrodes and is normally conformal to the electrodes and the underlying interlevel dielectric, is planarized by forming a layer of flowable oxide over the electrodes before forming the passivation. The flowable oxide, which is preferably very thin over the electrodes to minimize loss of sensitivity, provides a substantially planar upper surface, so that passivation formed on the flowable oxide is also substantially planar. Alternatively, a deposited oxide planarized by chemical mechanical polishing may be employed to planarize the surface on which a passivation stack is formed. The planarized passivation provides markedly improved scratch resistance.
Claims26
An integrated circuit structure, comprising:
- a dielectric layer;
- a plurality of capacitive electrodes overlying the dielectric layer and forming an array of sensors for capacitive coupling to an item placed proximate to the capacitive electrodes;
- a layer of oxide overlying the capacitive electrodes and portions of the dielectric layer between the capacitive electrodes, the oxide having a substantially planar upper surface;
- and
- passivation overlying the oxide.
A method of improving scratch resistance, comprising:
- forming a dielectric layer;
- forming a plurality of capacitive electrodes overlying the dielectric layer;
- forming a layer of oxide overlying the capacitive electrodes and the dielectric layer between the capacitive electrodes, the oxide having a substantially planar upper surface;
- and
- forming passivation overlying the oxide.
Scratch resistant integrated circuit protection for an array of capacitive electrodes, comprising:
- an oxide on the capacitive electrodes and between the capacitive electrodes, the oxide having a substantially planar upper surface;
- a silicon nitride layer over the oxide, the silicon nitride layer having a substantially planar upper surface;
- and
- a silicon carbide layer on the silicon nitride layer, the silicon carbide layer having a substantially planar upper surface.
Dependencies are inferred from the claim text.