Semiconductor integrated circuit having layout in which buffers or protection circuits are arranged in concentrated manner
Buffers are arranged in a concentrated manner in a region distant from pads. The region refers to a region in a main region of a semiconductor integrated circuit, except for a central processing unit, a non-volatile memory and a volatile memory. As the buffer requiring a large area is not provided around the pad, a pitch between the pads or a pitch between the pad and an internal circuit (such as the central processing unit) can be made smaller and hence a chip size can be reduced. Therefore, a semiconductor integrated circuit capable of achieving a reduced chip size can be provided.
1 . A semiconductor integrated circuit comprising:
a central processing unit;
a non-volatile memory storing information on processing performed in said central processing unit in a non-volatile manner;
a volatile memory temporarily storing said information;
a plurality of buffers or a plurality of protection circuits arranged in a region on a main surface of a semiconductor substrate lying between at least two of said central processing unit, said non-volatile memory and said volatile memory;
a plurality of pads provided corresponding to said plurality of buffers or said plurality of protection circuits, respectively; and
a plurality of metal interconnections directly connecting said plurality of buffers or said plurality of protection circuits to corresponding ones of said plurality of pads, respectively.
2 . The semiconductor integrated circuit according to claim 1 , having a multilayer interconnection, wherein
said plurality of metal interconnections are provided in an identical interconnection layer; and
said plurality of metal interconnections are located higher than any one of an interconnection layer having a metal interconnection in said central processing unit provided, an interconnection layer having a metal interconnection in said non-volatile memory provided, and an interconnection layer having a metal interconnection in said volatile memory provided, relative to said main surface.
3 . The semiconductor integrated circuit according to claim 2 , wherein
said plurality of buffers or said plurality of protection circuits are arranged in a single region on said main surface in a concentrated manner.
4 . The semiconductor integrated circuit according to claim 2 , wherein
said plurality of buffers or said plurality of protection circuits are arranged in a plurality of regions on said main surface in a distributed manner.
5 . The semiconductor integrated circuit according to claim 2 , wherein
said non-volatile memory has a plurality of first bit lines formed of metal;
said volatile memory has a plurality of second bit lines formed of metal;
said plurality of metal interconnections include a metal interconnection having a portion in parallel to any one of said plurality of first bit lines or any one of said plurality of second bit lines;
said semiconductor integrated circuit further comprises first and second dummy interconnections formed of metal and provided in the interconnection layer having said plurality of metal interconnections provided, so as to sandwich said portion in parallel from opposing sides thereof; and
said first and second dummy interconnections are supplied with a prescribed potential.
6 . The semiconductor integrated circuit according to claim 5 , wherein
said prescribed potential is a power supply potential or a ground potential.
7 . The semiconductor integrated circuit according to claim 5 , further comprising:
a plurality of sidewalls formed of an insulator and provided on respective side surfaces of each of said plurality of metal interconnections and on respective side surfaces of each of said first and second dummy interconnections; and
an insulating film covering said plurality of metal interconnections, said first and second dummy interconnections and said plurality of sidewalls, wherein
each of said plurality of sidewalls has a dielectric constant higher than that of said insulating film.
8 . The semiconductor integrated circuit according to claim 2 , wherein
said non-volatile memory has a plurality of first bit lines formed of metal;
said volatile memory has a plurality of second bit lines formed of metal; and
said plurality of metal interconnections include a metal interconnection formed to bend a plurality of times in such a manner as changing a bending direction alternately in a first direction in parallel to any one of said plurality of first bit lines or any one of said plurality of second bit lines and in a second direction different from said first direction, in the interconnection layer having said plurality of metal interconnections formed.