Semiconductor integrated circuit device with MISFETS using two drain impurities

Claim 2

A semiconductor integrated circuit device, comprising: a semiconductor substrate of a first conductivity type having a main surface; a first field effect transistor (FET) which is formed on said main surface, said first FET having a gate electrode formed on said main surface through an insulating film, source and drain regions formed at portions of said semiconductor substrate which correspond to both sides, respectively, of said gate electrode, and a corresponding channel forming portion disposed between said source and drain regions thereof, at least said drain region thereof having a first semiconductor region of a second conductivity type and a second semiconductor region, of said second conductivity type, which has a higher impurity concentration than that of said first semiconductor region, said first semiconductor region being disposed between said second semiconductor region and the portion of said semiconductor substrate in which the channel of said first FET is formed, wherein a first power potential is applied to said drain region of said first FET; and a second field effect transistor (FET) which is formed on said main surface, said second FET having a gate electrode formed on said main surface through an insulating film, source and drain regions formed at portions of said semiconductor substrate which correspond to both sides, respectively, of said gate electrode, and a corresponding channel forming portion disposed between said source and drain regions thereof, at least said drain region thereof having a third semiconductor region of said second conductivity type and a fourth semiconductor region, of said second conductivity type, which has a higher impurity concentration than that of said third semiconductor region, said third semiconductor region being disposed between said fourth semiconductor region and the portion of said semiconductor substrate in which the channel of said second FET is formed, wherein a second power potential which is higher in magnitude than said first power potential is applied to said drain region of said second FET, and wherein the value of the diffusion coefficient of an impurity element which is employed to form said first semiconductor region is smaller than that of an impurity element employed to form said third semiconductor region.

Claim 3

A semiconductor integrated circuit device according to claim 3, wherein the impurity employed to form said first, semiconductor, region is arsenic, and the impurity employed to form said third semiconductor region is phosphorus.

Claim 4

A semiconductor integrated circuit device according to claim 2, wherein the impurity employed to form said second and fourth semiconductor regions is arsenic.

Claim 5

A semiconductor integrated circuit device according to claim 3, wherein said first and second FETs comprise first and second metal insulator semiconductor field effect transistors (MISFETs), and wherein the gate electrode of said first MISFET has a length which is shorter than that of the gate electrode of said second MISFET.

Claim 6

A semiconductor integrated circuit device according to claim 3, which is a memory and wherein said first FET is employed to constitute a memory cell, and said second FET is employed to constitute a peripheral circuit.

Claim 7

A semiconductor integrated circuit device according to claim 5, wherein said memory is a read-only memory.

Claim 8

A semiconductor integrated circuit device according to claim 1, further comprising: side-walls formed at both sides, respectively, of each of said gate electrodes by a silicon oxide film which is formed by chemical vapor deposition.

Claim 9

A semiconductor integrated circuit device according to claim 7, wherein said first and third semiconductor regions of said first and second FETs are formed by using the corresponding gate electrodes as masks for introduction of an impurity, and said second and fourth semiconductor regions of said first and second FETs are formed by using the corresponding gate electrodes and said side-walls as masks for introduction of an impurity.

Claim 10

A semiconductor integrated circuit device according to claim 1, wherein said first, second, third and fourth semiconductor regions are formed so as to have respective depths extending into said semiconductor substrate from said main surface thereof such that the depth of said second semiconductor region is greater than that of said first semiconductor region, and the depth of said fourth semiconductor region is greater than that of said third semiconductor region.

Claim 11

A semiconductor integrated circuit device according to claim 1, wherein said second power potential is substantially 5 volts.

Claim 12

A semiconductor integrated circuit device according to claim 10, wherein said first power potential is less than 2 volts.

Claim 13

A semiconductor integrated circuit device having a semiconductor substrate, a memory cell formed on said semiconductor substrate, and a peripheral circuit formed on said semiconductor substrate, said semiconductor integrated circuit device comprising: a first field effect transistor (FET) constituting said memory cell, said first FET having a gate electrode formed on said semiconductor substrate through an insulating film, source and drain regions formed at portions of said semiconductor substrate which correspond to both sides, respectively, of said gate electrode and a corresponding channel forming portion disposed between said source and drain regions thereof, at least said drain region thereof having a first semiconductor region and a second semiconductor region which has a higher impurity concentration than that of said first semiconductor region, said first semiconductor region being disposed between said second semiconductor region and the portion of said semiconductor substrate in which the channel of said first FET is formed; and a second field effect transistor (FET) constituting said peripheral circuit, said second FET having a gate electrode formed on said semiconductor substrate through an insulating film, source and drain regions formed at portions of said semiconductor substrate which correspond to both sides, respectively, of said gate electrode, and a corresponding channel forming portion disposed between said source and drain regions thereof, at least said drain region thereof having a third semiconductor region and a fourth semiconductor region which has a higher impurity concentration than that of said third semiconductor region, said third semiconductor region being disposed between said fourth semiconductor region and the portion of said semiconductor substrate in which the channel of said second FET is formed, wherein the conductivity type of said first semiconductor region is the same as that of said third semiconductor region, and wherein the value of the diffusion coefficient of an impurity element which is introduced into said semiconductor substrate in order to form the first semiconductor region of said first FET is smaller than that of an impurity element introduced into said semiconductor substrate in order to form the third semiconductor region of said second FET.

Claim 14

A semiconductor integrated circuit device having a semiconductor substrate, a memory cell formed on said semiconductor substrate, and a peripheral circuit formed on said semiconductor substrate, said semiconductor integrated circuit device comprising: a first field effect transistor (FET) constituting said memory cell, said first FET having a gate electrode formed on said semiconductor substrate through an insulating film, source and drain regions formed at portions of said semiconductor substrate which correspond to both sides, respectively, of said gate electrode and a corresponding channel forming portion disposed between said source and drain regions thereof, at least said drain region thereof having a first semiconductor region and a second semiconductor region which has a higher impurity concentration than that of said first semiconductor region, said first semiconductor region being disposed between said second semiconductor region and the portion of said semiconductor substrate in which the channel of said first FET is formed; and a second field effect transistor (FET) constituting said peripheral circuit, said second FET having a gate electrode formed on said semiconductor substrate through an insulating film, source and drain regions formed at portions of said semiconductor substrate which correspond to both sides, respectively, of said gate electrode, and a corresponding channel forming portion disposed between said source and drain regions thereof, at least said drain region thereof having a third semiconductor region and a fourth semiconductor region which has a higher impurity concentration than that of said third semiconductor region, said third semiconductor region being disposed between said fourth semiconductor region and the portion of said semiconductor substrate in which the channel of said second FET is formed, wherein the conductivity type of said first semiconductor region is the same as that of said third semiconductor region, and wherein the value of the diffusion coefficient of an impurity element which is introduced into said semiconductor substrate in order to form the first semiconductor region of said first FET is smaller than that of an impurity element introduced into said semiconductor substrate in order to form the third semiconductor region of said second FET.

Claim 15

A semiconductor integrated circuit device according to claim 12, wherein said first and second FETs comprise first and second metal insulator semiconductor field effect transistors, and wherein the gate electrode of said first MISFET has a length which is shorter than that of the gate electrode of said second MISFET.

Claim 16

A semiconductor integrated circuit device according to claim 12, wherein the impurity employed to form said first, semiconductor region is arsenic, and the impurity employed to form said third semiconductor region is phosphorus.

Claim 17

A semiconductor integrated circuit device according to claim 14, wherein the impurity employed to form said second and fourth semiconductor regions is arsenic.

Claim 18

A semiconductor integrated circuit device according to claim 15, wherein each of said first and second FETs comprises an n-channel metal insulator semiconductor field effect transistor (n-channel MISFET).

Claim 19

A semiconductor integrated circuit device according to claim 16, wherein the gate electrode of said first MISFET has a length which is shorter than that of the gate electrode of said second MISFET.

Claim 20

A semiconductor integrated circuit device according to claim 12, which is a read-only memory.

Claim 21

A semiconductor integrated circuit device according to claim 12, further comprising: side-walls formed at both sides, respectively, of each of said gate electrodes by a silicon oxide film which is formed by chemical vapor deposition.

Claim 22

A semiconductor integrated circuit device according to claim 19, wherein said first and third semiconductor regions of said first and second FETs are formed by using the corresponding gate electrodes as masks for introduction of an impurity, and said second and fourth semiconductor regions of said first and second FETs are formed by using the corresponding gate electrodes and said side-walls as masks for introduction of an impurity.

Claim 23

A semiconductor integrated circuit device according to claim 20, wherein the impurity employed to form said second and fourth semiconductor regions is arsenic.

Claim 24

A semiconductor integrated circuit device according to claim 21, wherein said first and second FETs comprise first and second metal insulator semiconductor field effect transistors (MISFETs), and wherein the gate electrode of said first MISFET has a length which is shorter than that of the gate electrode of said second MISFET.

Claim 25

A semiconductor integrated circuit device according to claim 20, wherein said first, second, third and fourth semiconductor regions are formed so as to have respective depths extending into said semiconductor substrate from said main surface thereof such that the depth of said second semiconductor region is greater than that of said first semiconductor region, and the depth of said fourth semiconductor region is greater than that of said third semiconductor region.

Claim 26

A semiconductor integrated circuit device according to claim 23, wherein the impurity employed to form said second and fourth semiconductor regions is arsenic.

Claim 27

A semiconductor integrated circuit device according to claim 12, wherein said first, second, third and fourth semiconductor regions are formed so as to have respective depths extending into said semiconductor substrate from said main surface thereof such that the depth of said second semiconductor region is greater than that of said first semiconductor region, and the depth of said fourth semiconductor region is greater than that of said third semiconductor region.

Claim 28

A semiconductor integrated circuit device according to claim 12, wherein a first power potential is supplied to the drain region of said first FET, and a second power potential which is higher in magnitude than said first power potential is applied to the drain region of said second FET.

Claim 29

A semiconductor integrated circuit device according to claim 26, wherein said second power potential is substantially 5 volts.

Claim 30

A semiconductor integrated circuit device according to claim 27, wherein said first power potential is less than 2 volts.

Claim 31

A semiconductor integrated circuit device according to claim 12, wherein said first and second FETs are n-type metal-oxide-semiconductor transistor devices.

Claim 32

A read only memory device having a semiconductor substrate of a first conductivity type and which semiconductor substrate has a main surface, a memory cell formed on said main surface of said semiconductor substrate, and a peripheral circuit formed at a different part of said semiconductor substrate on said main surface thereof, said read only memory device comprising: a first field effect transistor (FET) constituting said memory cell, said first FET having a gate electrode formed on said main surface through an insulating film, source and drain regions formed at portions of said semiconductor substrate which correspond to both sides, respectively, of said gate electrode, and a corresponding channel forming portion disposed between said source and drain regions thereof, at least said drain region thereof having a first semiconductor region of a second conductivity type and a second semiconductor region, of said second conductivity type, which has a higher impurity concentration than that of said first semiconductor region, said first semiconductor region being disposed between said second semiconductor region and the portion of said semiconductor substrate in which the channel of said first FET is formed; and a second field effect transistor (FET) for constituting said peripheral circuit, said second FET having a gate electrode formed on said main surface through an insulating film, source and drain regions formed at portions of said semiconductor substrate which correspond to both sides, respectively, of said gate electrode, and a corresponding channel forming portion disposed between said source and drain regions thereof, at least said drain region thereof having a third semiconductor region of said conductivity type and a fourth semiconductor region, of said second conductivity type, which has a higher impurity concentration than that of said third semiconductor region, said third semiconductor region being disposed between said fourth semiconductor region and the portion of said semiconductor substrate in which the channel of said second FET is formed, wherein the value of the diffusion coefficient of an impurity element which is employed to form said first semiconductor region is smaller than that of an impurity element employed to form said third semiconductor region.

Claim 33

A read only memory device having a semiconductor substrate of a first conductivity type and which semiconductor substrate has a main surface, a memory cell formed on said main surface of said semiconductor substrate, and a peripheral circuit formed at a different part of said semiconductor substrate on said main surface thereof, said read only memory device comprising: a first field effect transistor (FET) constituting said memory cell, said first FET having a gate electrode formed on said main surface through an insulating film, source and drain regions formed at portions of said semiconductor substrate which correspond to both sides, respectively, of said gate electrode, and a corresponding channel forming portion disposed between said source and drain regions thereof, at least said drain region thereof having a first semiconductor region of a second conductivity type and a second semiconductor region, of said second conductivity type, which has a higher impurity concentration than that of said first semiconductor region, said first semiconductor region being disposed between said second semiconductor region and the portion of said semiconductor substrate in which the channel of said first FET is formed; and a second field effect transistor (FET) for constituting said peripheral circuit, said second FET having a gate electrode formed on said main surface through an insulating film, source and drain regions formed at portions of said semiconductor substrate which correspond to both sides, respectively, of said gate electrode, and a corresponding channel forming portion disposed between said source and drain regions thereof, at least said drain region thereof having a third semiconductor region of said conductivity type and a fourth semiconductor region, of said second conductivity type, which has a higher impurity concentration than that of said third semiconductor region, said third semiconductor region being disposed between said fourth semiconductor region and the portion of said semiconductor substrate in which the channel of said second FET is formed, wherein the value of the diffusion coefficient of an impurity element which is employed to form said first semiconductor region is smaller than that of an impurity element employed to form said third semiconductor region.

Claim 34

A semiconductor integrated circuit device according to claim 30, wherein the impurity employed to form said first semiconductor regions is arsenic, and the impurity employed to form said third semiconductor region is phosphorus.

Claim 35

A semiconductor integrated circuit device according to claim 31, wherein the impurity employed to form said second and fourth semiconductor regions is arsenic.

Claim 36

A semiconductor integrated circuit device according to claim 30, wherein said first and second FETs comprise first and second metal insulator semiconductor field effect transistors (MISFETs), and wherein the gate electrode of said first MISFET has a length which is shorter than that of the gate electrode of said second MISFET.

Claim 37

A semiconductor integrated circuit device according to claim 30, wherein a first power potential is supplied to the drain region of said first FET, and a second power potential which is higher in magnitude than said first power potential is applied to the drain region of said second FET.

Claim 38

A semiconductor integrated circuit device according to claim 34, wherein said second power potential is substantially 5 volts.

Claim 39

A semiconductor integrated circuit device according to claim 35, wherein said first power potential is less than 2 volts.

Claim 40

A semiconductor integrated circuit device having a peripheral circuit and a memory cell array, said memory cell array having cell rows each formed by arranging first field effect transistors (FETs) in series, said semiconductor integrated circuit device comprising: a semiconductor substrate of a first conductivity type having a main surface; wherein said first FETs are formed on said main surface, each one of said first FETs having a gate electrode formed on said main surface through an insulating film, source and drain regions formed at portions of said semiconductor substrate which correspond to both sides, respectively, of said gate electrode, and a corresponding channel forming portion disposed between said source and drain regions thereof, at least said drain region thereof having a first semiconductor region of a second conductivity type and a second semiconductor region, of said second conductivity type, which has a higher impurity concentration than that of said first semiconductor region, said first semiconductor region being disposed between said second semiconductor region and the portion of said semiconductor substrate in which the channel of said first FET is formed; and a second field effect transistor (FET), for constituting said peripheral circuit, which is formed on said main surface, said second FET having a gate electrode formed on said main surface through an insulating film, source and drain regions formed at portions of said semiconductor substrate which correspond to both sides, respectively, of said gate electrode, and a corresponding channel forming portion disposed between said source and drain regions thereof, at least said drain region thereof having a third semiconductor region of said second conductivity type and a fourth semiconductor region, of said second conductivity type, which has a higher impurity concentration than that of said third semiconductor region, said third semiconductor region being disposed between said fourth semiconductor region and the portion of said semiconductor substrate in which the channel of said second FET is formed, wherein the value of the diffusion coefficient of an impurity element which is employed to form said first semiconductor region associated with each of said first FETs is smaller than that of an impurity element employed to form said third semiconductor region.

Claim 41

A semiconductor integrated circuit device having a peripheral circuit and a memory cell array, said memory cell array having cell rows each formed by arranging first field effect transistors (FETs) in series, said semiconductor integrated circuit device comprising: a semiconductor substrate of a first conductivity type having a main surface; wherein said first FETs are formed on said main surface, each one of said first FETs having a gate electrode formed on said main surface through an insulating film, source and drain regions formed at portions of said semiconductor substrate which correspond to both sides, respectively, of said gate electrode, and a corresponding channel forming portion disposed between said source and drain regions thereof, at least said drain region thereof having a first semiconductor region of a second conductivity type and a second semiconductor region, of said second conductivity type, which has a higher impurity concentration than that of said first semiconductor region, said first semiconductor region being disposed between said second semiconductor region and the portion of said semiconductor substrate in which the channel of said first FET is formed; and a second field effect transistor (FET), for constituting said peripheral circuit, which is formed on said main surface, said second FET having a gate electrode formed on said main surface through an insulating film, source and drain regions formed at portions of said semiconductor substrate which correspond to both sides, respectively, of said gate electrode, and a corresponding channel forming portion disposed between said source and drain regions thereof, at least said drain region thereof having a third semiconductor region of said second conductivity type and a fourth semiconductor region, of said second conductivity type, which has a higher impurity concentration than that of said third semiconductor region, said third semiconductor region being disposed between said fourth semiconductor region and the portion of said semiconductor substrate in which the channel of said second FET is formed, wherein the value of the diffusion coefficient of an impurity element which is employed to form said first semiconductor region associated with each of said first FETs is smaller than that of an impurity element employed to form said third semiconductor region.

Claim 42

A semiconductor integrated circuit device according to claim 37, wherein the impurity employed to form said first semiconductor regions is arsenic, and the impurity employed to form said third semiconductor region is phosphorus.

Claim 43

A semiconductor integrated circuit device according to claim 38, wherein the impurity employed to form said second and fourth semiconductor regions is arsenic.

Claim 44

A semiconductor integrated circuit device according to claim 37, wherein each of said first FETs and said second FET are comprised of first metal insulator semiconductor field effect transistors (MISFETs) and a second metal insulator semiconductor field effect transistor, respectively, and wherein the gate electrode of each one of said first MISFETs has a length which is shorter than that of the gate electrode of said second MISFET.

Claim 45

A semiconductor integrated circuit device according to claim 37, wherein a first power potential is supplied to a drain region of one of said series-arranged first FETs of each cell row; and a second power potential which is higher in magnitude than said first power potential is applied to a drain region of said second FET.

Claim 46

A semiconductor integrated circuit device according to claim 41, wherein said second power potential is substantially 5 volts.

Claim 47

A semiconductor integrated circuit device according to claim 42, wherein said first power potential is less than 2 volts.

Claim 48

A semiconductor integrated circuit device according to claim 41, wherein said first power potential is applied to the drain of that one of said first FETs disposed at one end of each cell row, and a reference ground potential is applied to the source of the first FET in each row located at the other end thereof, said one end of each row being coupled to one end of a corresponding data line which controllably provides said first power potential to the corresponding memory cell row.