US 6,548,231 B1Granted

Enhanced passivation scheme for post metal etch clean process

AssigneeChartered Semiconductor Manufacturing Ltd.

InventorsAik Hon Goh, Xin Zhang, Carol Goh

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Abstract

A two step passivation procedure, used to remove chlorine from polymer layers formed on the sides of metal structures, prior to removal of the defining photoresist shape, and of the polymer layers, has been developed. The procedure features a first passivation step, performed at a low substrate temperature, (100-140° C.) at low RF power, (150 to 250 watts), and using a 2 to 1 ratio of oxygen to water, resulting in removal of corrosion causing chlorine, from the polymer layers, located on the sides of a first group of defined metal structures, which in turn reside at the edge of a semiconductor substrate. A second passivation step, of the two step passivation procedure, is then performed using water only, at higher substrate temperature, (200-250° C.), resulting in removal of chlorine from polymer layers located on the sides of a second set of metal structures, which reside at the center of the semiconductor substrate. Removal of the masking photoresist shape, and removal of the polymer layers, now without chlorine, is then performed.

Claims21

Dependent claims

A method of removing a masking photoresist shape from the top surface of a defined metal structure, and removing polymer layers formed on the sides of the defined metal structure, on semiconductor substrate, comprising the steps of:

providing metal structures, each with an overlying defining photoresist shape, and each with polymer layers comprised with incorporated chlorine, located on the sides of each metal structure;
performing a first step of a two step passivation procedure at a first temperature, a temperature of 140° C. or less, in a oxygen-water ambient, with said first step of said two step procedure removing chlorine from said polymer layers located on the sides of a first group of metal structures, wherein said first group of metal structures are located near an edge of said semiconductor substrate, and wherein said first step of said two step passivation procedure does not completely remove chlorine from said polymer layers located on the sides of a second group of metal structures, wherein said second group of metal structures are located near a center of said semiconductor substrate,
performing a second step of said two step passivation procedure at a second temperature, with said second temperature higher than said first temperature, in a water only ambient, to remove remaining chlorine from said polymer layers located on the sides of said second group of metal structures;
removing said defining photoresist shape;
and
removing said polymer layers from the sides of said first group, and from the sides of said second group, of said metal structures.

3 more elements

A method of removing a masking photoresist shape from a top surface of defined metal structures, and removing chlorine containing polymer layers located on the sides of the defined metal structures, using a two step passivation procedure, comprising the steps of

providing said defined metal structures, underlying said masking photoresist shape, with said chlorine containing polymer layers located on the sides of said defined metal structures;
performing a first passivation step of said two step passivation procedure, in an oxygen-water ambient, performed at a low, first temperature, below 140° C., to remove chlorine from said chlorine containing polymer layers that reside on the sides of a first set of metal structures, wherein said first set of metal structures are located near an edge of a semiconductor substrate, with said first passivation step of said two step passivation procedure not completely removing chlorine from chlorine containing polymer layers located on the sides of a second set of metal structures, located near a center of said semiconductor substrate;
performing a second passivation step of said two step passivation procedure, in a water only ambient to completely remove chlorine from said chlorine containing polymer layers that reside on the sides of said second set of metal structures, with said second passivation step performed at a higher temperature than said first passivation step, between about 200 to 250° C.;
removing said masking photoresist shape from top surface of said first set of metal structures, and from top surface of said second set of metal structures;
and
removing polymer layers from the sides of said first set of metal structures, and from the sides of said second set of metal structures.

3 more elements

Dependencies are inferred from the claim text.