Methods Of Forming A Mask And Methods Of Correcting Intra-Field Variation Across A Mask Design Used In Photolithographic Processing

A method of forming a mask, comprising:

• creating a difference map between a desired intra-field pattern that is to be formed on substrates and an intra-field signature pattern, the intra-field signature pattern representing a pattern formed on an example substrate by an exposure field using an example E-beam-written mask;
• determining modifications to formation of mask features to be made using an E-beam mask writer if forming a modified E-beam-written mask having mask features modified from that of the example E-beam-written mask that will improve substrate feature variation identified in the difference map;
• programming the E-beam mask writer using the determined modifications to improve the substrate feature variation identified in the difference map;
• using the programmed E-beam mask writer to form the modified E-beam-written mask having the modified mask features;
• photolithographically processing one or more substrates using the modified E-beam-written mask;
• and
• wherein determining the modifications comprises using a feedback loop in creating multiple difference maps between the desired intra-field pattern and multiple intra-field signature patterns derived by simulation from forming different respective theoretical E-beam-written masks, wherein at least some subsequent of the theoretical E-beam-written masks would improve substrate feature variation identified in its difference map.

A method of forming a mask, comprising:

• creating a difference map between a desired intra-field pattern that is to be formed on substrates and an intra-field signature pattern, the intra-field signature pattern representing a pattern formed on an example substrate by an exposure field using an example E-beam-written mask;
• determining modifications to formation of mask features to be made using an E-beam mask writer if forming a modified E-beam-written mask having mask features modified from that of the example E-beam-written mask that will improve substrate feature variation identified in the difference map;
• programming the E-beam mask writer using the determined modifications to improve the substrate feature variation identified in the difference map;
• using the programmed E-beam mask writer to form the modified E-beam-written mask having the modified mask features;
• photolithographically processing one or more substrates using the modified E-beam-written mask;
• and
• wherein determining the modifications comprises using a feedback loop in creating multiple difference maps between the desired intra-field pattern and multiple intra-field signature patterns derived by physical trial from forming different respective physical E-beam-written masks, wherein at least some subsequent of the physical E-beam-written masks improve substrate feature variation identified in its difference map.

A method of forming a mask, comprising:

• creating a difference map between a desired intra-field pattern that is to be formed on semiconductor substrates and an intra-field signature pattern, the intra-field signature pattern being formed by photolithographically patterning an example substrate with an exposure field using an example E-beam-written mask and scanning the patterned example substrate, creating the difference map comprising creating at least two matrices of critical dimension (CD) values along two different directions that are orthogonal relative one another;
• determining modifications to formation of mask features to be made using an E-beam mask writer if forming a modified E-beam-written mask having mask features modified from that of the example E-beam-written mask that will improve substrate feature variation identified in the difference map, determining of the modifications comprising determining relationships among orthogonal x, y dimensions and variable E-beam dose if forming the modified mask features using multiple E-beam exposures in forming individual of the modified mask features;
• programming the E-beam mask writer using the determined modifications to improve the substrate feature variation identified in the difference map;
• using the programmed E-beam mask writer to form the modified E-beam-written mask having the modified mask features;
• and
• photolithographically processing one or more semiconductor substrates using the modified E-beam-written mask.