Accuracy of optical metrology measurements

A system for using an optically tunable soft mask (OTSM) comprising:

• a transfer subsystem for providing a substrate having a material layer thereon;
• and
• a lithography subsystem for depositing an OTSM on the material layer, wherein the OTSM comprises a first set of optical properties optimized, tuned and/or enhanced for an exposure process and a second set of optical properties optimized, tuned and/or enhanced for a measurement process, the OTSM comprising a polymer, an acid generator compound, and a metrology enhancing material coupled to the polymer using a protecting group wherein the metrology enhancing material establishes the second set of optical properties after being de-protected;
• for exposing the OTSM to patterned radiation created using a reticle and a radiation source, thereby activating an acid in the acid generator compound;
• for developing the exposed OTSM, thereby creating a plurality of un-enhanced structures in the OTSM;
• and for creating a plurality of enhanced structures in the OTSM by enhancing the plurality of un-enhanced structures in the OTSM, wherein the metrology enhancing material is de-protected during the developing process thereby creating the plurality of enhanced structures, wherein at least one of the plurality of enhanced structures is characterized by the second set of optical properties.

A method of using an optically tunable soft mask (OTSM) comprising:

• providing a substrate having a material layer thereon;
• depositing an OTSM on the material layer, wherein the OTSM comprises a first set of optical properties optimized, tuned and/or enhanced for an exposure process and a second set of optical properties optimized, tuned and/or enhanced for a measurement process, the OTSM comprising a polymer, an acid generator compound, and a metrology enhancing material coupled to the polymer, wherein the metrology enhancing material provides metrology-enhancing properties after being de-protected;
• exposing the OTSM to radiation using a mask and a radiation source thereby creating exposed regions and unexposed regions in the OTSM, wherein a solubility change occurs in the unexposed regions of the OTSM;
• developing the exposed OTSM, wherein the un-exposed regions are removed and the exposed regions are used to create a plurality of structures in the OTSM;
• and
• enhancing the plurality of structures in the OTSM, wherein the metrology enhancing material is de-protected during the developing process thereby creating a plurality of enhanced structures, wherein at least one of the plurality of enhanced structures is characterized by the second set of optical properties.

A method of using an optically tunable soft mask (OTSM) comprising:

• providing a substrate having a material layer thereon;
• depositing an OTSM on the material layer, wherein the OTSM comprises a first set of optical properties optimized, tuned and/or enhanced for an exposure process and a second set of optical properties optimized, tuned and/or enhanced for a measurement process, the OTSM comprising a polymer, an acid generator compound, and a metrology enhancing material coupled to the polymer using a protecting group, wherein the metrology enhancing material provides metrology-enhancing properties after being de-protected;
• exposing the OTSM to radiation using a reticle and a radiation source thereby creating exposed regions and unexposed regions in the OTSM, wherein a solubility change occurs in the exposed regions of the OTSM;
• developing the exposed OTSM, wherein the exposed regions are removed and the unexposed regions are used to create a plurality of structures in the OTSM;
• and
• creating a plurality of enhanced structures in the OTSM by enhancing the plurality of un-enhanced structures in the OTSM, wherein the metrology enhancing material is de-protected during the exposure process thereby creating the plurality of enhanced structures, wherein at least one of the plurality of enhanced structures is characterized by the second set of optical properties.