Semiconductor memory
A semiconductor memory having a memory cell structure capable of reducing soft error without complicating a circuit configuration. Specifically, an inverter (I 1 ) consists of a NMOS transistor (N 1 ) and a PMOS transistor (P 1 ), and an inverter (I 2 ) consists of a NMOS transistor (N 2 ) and a PMOS transistor (P 2 ). The inverters (I 1, I 2 ) are subjected to cross section. The NMOS transistor (N 1 ) is formed within a P well region (PW 0 ), and the NMOS transistor (N 2 ) is formed within a P well region (PW 1 ). The P well regions (PW 0, PW 1 ) are oppositely disposed with an N well region (NW) interposed therebetween.
1. A semiconductor memory comprising:
a memory cell having first and second storage terminals storing information of logic levels complementary to each other;
a power supply wiring supplying a predetermined power supply voltage to said memory cell;
first and second pairs of bit lines each electrically connected to said first and second storage terminals of said memory cell, when selected; and
first and second word lines connected to said memory cell, said first pair of bit lines connected to said memory cell and at least reading out data stored at said first and second storage terminals from said memory cell in response to a signal on said first word line, and said second pair of bit lines connected to said memory cell and at least reading out data stored at said first and second storage terminals from said memory cell in response to a signal on said second word line, wherein
said first and second pairs of bit lines and said power supply wiring are provided in parallel to each other, with said power supply wiring interposed between said first and second pairs of bit lines.
2. The semiconductor memory according to claim 1 , further comprising:
first and second ground wirings each supplying a predetermined ground potential to said memory cell, wherein
said first pair of bit lines and said first ground wiring are provided in parallel to each other, with said first ground wiring interposed between said first pair of bit lines, and
said second pair of bit lines and said second ground wiring are provided in parallel to each other, with said second ground wiring interposed between said second pair of bit lines.
3. The semiconductor memory according to claim 1 , wherein
said memory cell is formed on first and second P wells and an N well interposed between said first and second P wells in a first direction, and said power supply wiring extending along a second direction vertical to said first direction is formed on said N well.
4. A semiconductor memory comprising:
a memory cell having first and second storage terminals storing information of logic levels complementary to each other;
a power supply wiring supplying a power supply voltage to said memory cell;
a first pair of bit lines each connected to said first and second storage terminals of said memory cell via a first and a second access transistors, respectively;
a second pair of bit lines each connected to said first and second storage terminals of said memory cell via a third and a fourth access transistors, respectively;
a first word line connected to gates of said first and said second transistors, and
a second word line connected to gates of said third and said fourth transistors, said first pair of bit lines connected to said memory cell and at least reading out data stored at said first and second storage terminals from said memory cell in response to a signal on said first word line, and said second pair of bit lines connected to said memory cell and at least reading out data stored at said first and second storage terminals from said memory cell in response to a signal on said second word line, wherein
said first and second pairs of bit lines and said power supply wiring are provided in parallel to each other, with said power supply wiring interposed between said first and second pairs of bit lines.
5. The semiconductor memory according to claim 4, further comprising:
first and second ground wirings each supplying a ground potential to said memory cell, wherein
said first pair of bit lines and said first ground wiring are provided in parallel to each other, with said first ground wiring interposed between said first pair of bit lines, and
said second pair of bit lines and said second ground wiring are provided in parallel to each other, with said second ground wiring interposed between said second pair of bit lines.
6. The semiconductor memory according to claim 4, wherein
said memory cell is formed on first and second P wells and an N well interposed between said first and second P wells in a first direction, and said power supply wiring extending along a second direction crossing with said first direction is formed on said N well.
7. A semiconductor memory comprising:
a memory cell having first and second storage terminals storing information of logic levels complementary to each other;
first and second ground wirings each supplying a ground potential to said memory cell;
a first pair of bit lines each connected to said first and second storage terminals of said memory cell via a first and a second access transistors, respectively;
a second pair of bit lines each connected to said first and second storage terminals of said memory cell via a third and a fourth access transistors, respectively; and
first and second word lines connected to said memory cell, said first pair of bit lines connected to said memory cell and at least reading out data stored at said first and second storage terminals from said memory cell in response to a signal on said first word line, and said second pair of bit lines connected to said memory cell and at least reading out data stored at said first and second storage terminals from said memory cell in response to a signal on said second word line, wherein
said first pair of bit lines and said first ground wiring are provided in parallel to each other, with said first ground wiring interposed between said first pair of bit lines, and
said second pair of bit lines and said second ground wiring are provided in parallel to each other, with said second ground wiring interposed between said second pair of bit lines.
8. The semiconductor memory according to claim 7, wherein
said memory cell is formed on first and second P wells and an N well interposed between said first and second P wells in a first direction, and said first and second ground wirings extending along a second direction crossing to said first direction is formed on said N well.