Analytical model for predicting the operating process window for lithographic patterning techniques based on photoresist trim technology

A method of trimming photoresist to form a mask for a layer of a semiconductor device comprising trimming a photoresist element substantially in accordance with:

• w0=(h0−Rvtmax)ARmax+Rhtmax
• where
• w0=width of photoresist prior to trim;
• h0=height of photoresist prior to trim;
• Rv=resist vertical etch rate;
• tmax=maximum etch time to reach resist vertical etch limit;
• ARmax=maximum allowable aspect ratio;
• Rh=horizontal resist etch rate.

A method of trimming photoresist to form a mask for a layer of a semiconductor device comprising trimming a photoresist element substantially in accordance with:

• wmin1=(h0−Rvt)/ARmax
• where
• wmin1=minimum width of photoresist (FICD) at maximum AR (nm);
• h0=initial photoresist thickness or height prior to trim;
• Rv=resist vertical etch rate (nm/sec);
• t=time;
• ARmax=maximum allowable aspect ratio.

A method of trimming photoresist to form a mask for a layer of a semiconductor device comprising trimming a photoresist element substantially in accordance with:

• wmin2=w0−Rh(h0−hmin)/Rv
• where
• wmin2=minimum width of photoresist (FICD) at resist vertical erosion or etch limit (nm);
• w0=width of photoresist prior to trim (DICD) (nm);
• Rh=resist horizontal etch rate (nm/sec);
• h0=initial photoresist thickness or height prior to trim (nm);
• hmin=minimum post-trim photoresist thickness (height) allowed (nm);
• Rv=resist vertical etch rate (nm/sec).