05328810 is referenced by 538 patents and cites 7 patents.

The process starts with a primary mask, which may be characterized as a pattern of parallel, photoresist strips having substantially vertical edges, each having a minimum feature width F, and being separated from neighboring strips by a minimum space width which is also approximately equal to F. From this primary mask, a set of expendable mandrel strips is created either directly or indirectly. The set of mandrel strips may be characterized as a pattern of parallel strips, each having a feature width of F/2, and with neighboring strips being spaced from one another by a space width equal to 3/2F. A conformal stringer layer is then deposited. The stringer layer material is selected such that it may be etched with a high degree of selectivity with regard to both the mandrel strips and an underlying layer which will ultimately be patterned using a resultant, reduced-pitch mask. The stringer layer is then anisotropically etched to the point where the top of each mandrel strip is exposed. The mandrel strips are then removed with an appropriate etch. A pattern of stringer strips remains which can then be used as a half-pitch mask to pattern the underlying layer. This process may also be repeated, starting with the half-pitch mask and creating a quarter-pitch mask, etc. As can be seen, this technique permits a reduction in the minimum pitch of the primary mask by a factor of 2.sup.-N (where N is an integer 1, 2, 3, . . . ).

Title
Method for reducing, by a factor or 2.sup.-N, the minimum masking pitch of a photolithographic process
Application Number
519992
Publication Number
5328810
Application Date
November 25, 1992
Publication Date
July 12, 1994
Inventor
David A Cathey
Boise
ID, US
Randal W Chance
Boise
ID, US
Tyler A Lowrey
Boise
ID, US
Agent
Angus C Fox III
Assignee
Micron Technology
ID, US
IPC
G03C 5/00
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