Polyelectrolyte dispensing polishing pad, production thereof and method of polishing a substrate

A method of chemical mechanical polishing of a surface of a semiconductor wafer, which surface comprises the surface of an upper layer of a member selected from the group consisting of a dielectric oxide layer and a metallic layer, overlying a lower layer of silicon nitride, to remove substantially completely the upper layer and expose substantially completely the lower layer of silicon nitride as a substantially intact layer essentially without removing any portion of the lower layer of silicon nitride, comprising the steps of:

• (a) maintaining the surface of the upper layer in the presence of an aqueous polishing liquid in frictional sliding contact with a polishing layer comprising friction erodible binder material containing substantially uniformly dispersed therein both a plurality of abrasive particles and a water soluble ionizable polyelectrolyte, such that during the polishing of the surface of the upper layer by the polishing layer the binder material is incrementally eroded and in turn the abrasive particles and polyelectrolyte are incrementally released into direct contact with the surface of the upper layer;
• and
• (b) continuing the maintaining of the surface of the upper layer in the presence of the aqueous polishing liquid in frictional sliding contact with the polishing layer until the upper layer is substantially completely removed and the lower layer of silicon nitride is thereby substantially completely exposed as a substantially intact layer essentially without removing any portion of the lower layer of silicon nitride.

A method of chemical mechanical polishing of a surface of a semiconductor wafer, which surface comprises the surface of an upper layer of silicon dioxide overlying a lower layer of silicon nitride, to remove substantially completely the upper layer of silicon dioxide and expose substantially completely the lower layer of silicon nitride as a substantially intact layer essentially without removing any portion of the lower layer of silicon nitride, comprising the steps of:

• (a) maintaining the surface of the upper layer of silicon dioxide in the presence of an aqueous polishing liquid in frictional sliding contact with a polishing layer comprising friction erodible binder material containing substantially uniformly dispersed therein both a plurality of abrasive particles and a water soluble ionizable polyelectrolyte, such that during the polishing of the surface of the upper layer of silicon dioxide by the polishing layer the binder material is incrementally eroded and in turn the abrasive particles and polyelectrolyte are incrementally released into direct contact with the surface of the upper layer of silicon dioxide;
• and
• (b) continuing the maintaining of the surface of the upper layer of silicon dioxide in the presence of the aqueous polishing liquid in frictional sliding contact with the polishing layer until the upper layer of silicon dioxide is substantially completely removed and the lower layer of silicon nitride is thereby substantially completely exposed as a substantially intact layer essentially without removing any portion of the lower layer of silicon nitride.

A method of chemical mechanical polishing of a surface of a semiconductor wafer, which surface comprises the surface of an upper layer of a member selected from the group consisting of a dielectric oxide layer and a metallic layer, overlying a lower layer of silicon nitride, to remove substantially completely the upper layer and expose substantially completely the lower layer of silicon nitride as a substantially intact layer essentially without removing any portion of the lower layer of silicon nitride, comprising the steps of:

• (a) maintaining the surface of the upper layer in the presence of an aqueous polishing liquid in frictional sliding contact with a polishing layer comprising friction erodible binder material containing substantially uniformly dispersed therein both a plurality of abrasive particles and at least one water soluble ionizable electrolyte substance in a chemical mechanical polishing effective amount and selected from the group consisting of (i) inorganic electrolytes, (ii) organic electrolytes and (iii) polyelectrolytes, such that during the polishing of the surface of the upper layer by the polishing layer the binder material is incrementally eroded and in turn the abrasive particles and electrolyte substance are incrementally released into direct contact with the surface of the upper layer;
• and
• (b) continuing the maintaining of the surface of the upper layer in the presence of the aqueous polishing liquid in frictional sliding contact with the polishing layer until the upper layer is substantially completely removed and the lower layer of silicon nitride is thereby substantially completely exposed as a substantially intact layer essentially without removing any portion of the lower layer of silicon nitride;
• wherein the electrolyte substance is released sufficiently for coating the lower layer of silicon nitride therewith as the lower layer of silicon nitride becomes exposed during the polishing for thereby inhibiting removal of the lower layer of silicon nitride thereat.