Semiconductor device comprising variable-sized contact, method of forming same, and apparatus comprising same

Abstract

A semiconductor device comprises an electrical contact designed to reduce a contact resistance. The electrical contact has a size that varies according to a length of a region where the contact is to be formed.

1 . A semiconductor device, comprising:
 a lower conductive portion formed on a substrate;   an insulating layer formed on the lower conductive portion;   an upper conductive portion formed on the insulating layer and overlapping the lower conductive portion in a first direction to define an overlap region having a first length; and   a variable-sized contact connecting the lower conductive portion and the upper conductive portion and having a horizontal cross-sectional width in the first direction that varies according to the first length.   
     
     
         2 . The semiconductor device of  claim 1 , wherein, where the first length is greater than a minimum length required for forming one fixed contact and is less than a minimum length required for forming two fixed contacts, the variable-sized contact is formed with a horizontal cross-sectional width between a horizontal cross-sectional width of a fixed contact and a sum of a distance between two fixed contacts and horizontal cross-sectional widths of the two fixed contacts. 
     
     
         3 . The semiconductor device of  claim 1 , wherein, where the first length is A, a horizontal cross-sectional width of a fixed contact is B, and a distance between two fixed contacts is C, the horizontal cross-sectional width of the variable-sized contact is between B and 2*B+C. 
     
     
         4 . The semiconductor device of  claim 3 , wherein a minimum horizontal cross-sectional width of the variable-sized contact is within a range of 1.5*B to 2*B. 
     
     
         5 . The semiconductor device of  claim 3 , wherein the overlap region has a second length of A′ in a second direction perpendicular to the first direction, the fixed contact has a horizontal cross-sectional width of B′ in the second direction, and the horizontal cross-sectional width of the variable-sized contact in the second direction is between B′ and 2*B′+C. 
     
     
         6 . The semiconductor device of  claim 1 , further comprising a predetermined number of variable-sized contacts formed with a first horizontal cross-sectional width that is less than a sum of a distance between n fixed contacts and horizontal cross-sectional widths of the n fixed contacts, where n is an integer greater than 2. 
     
     
         7 . The semiconductor device of  claim 6 , wherein the variable-sized contacts comprise a combination of a first variable-sized contact having the first horizontal cross-sectional width and second variable-sized contacts having a second horizontal cross-sectional width that is less than a sum of a distance between m fixed contacts and horizontal cross-sectional widths of the m fixed contacts, where m is an integer smaller than n. 
     
     
         8 . The semiconductor device of  claim 1 , wherein the lower and upper conductive portions each comprise a semiconductor or a metal, and the electrical contact comprises a metal.