Etch failure prediction based on wafer resist top loss

An apparatus comprising:

• at least one processor;
• and
• at least one memory including computer program code for one or more programs,
• the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus to perform at least the following,
• determine first and second features of an integrated circuit (IC) design;
• determine, prior to a mask write and to wafer print down of a resulting IC circuit corresponding to the IC design, a thickness of a resist layer of the IC design indicated by a profile of an aerial image of the IC design;
• determine a threshold value based on the thickness by determining a thickness of the resist layer within a region of the IC design containing the first and second features, wherein the threshold value is determined according to the thickness within the region;
• compare the threshold value to a separation distance between the first and second features prior to the mask write and to wafer print down;
• determine a nominal threshold value for the IC design, wherein the threshold value is further based on the nominal threshold;
• and
• compare each feature within the region of the IC design with the threshold value;
• wherein the threshold value is a summation of the nominal threshold value and a weighted value of the thickness.

A method comprising:

• determining a plurality of features in first and second window regions of an integrated circuit (IC) design;
• determining, prior to a mask write and to wafer print down of a resulting IC circuit corresponding to the IC design, a first and second thickness of a resist layer for the first and second window regions, respectively, indicated by a profile of an aerial image of the IC design;
• determining first and second window threshold values for the first and second window regions, respectively, based on the first and second thicknesses, respectively, and a nominal threshold value for the IC design;
• determining first and second separation distances between features of the plurality of features within the first and second window regions, respectively;
• and
• comparing, in real-time and by a processor, the first and second window threshold values to the first and second separation distances, respectively, before the mask write and wafer printing,
• wherein the first and second window threshold values are summations of the nominal threshold value and a weighted value of the first and second thickness, respectively.