Matsushita Electric Industrial Co., Ltd.

Akira Hiroki

Shinji Odanaka

Kazumi Kurimoto

Atsushi Hori

Isao Miyanaga

Kyoji Yamashita

A semiconductor device of the invention is formed so that the impurity concentration of a semiconductor substrate ( ) under a source diffusion layer ( ) is lower than the impurity concentration on a source side of a p-type impurity diffusion layer ( ). Therefore, in the semiconductor device of the invention, the junction capacitance of the p-n junction between the source and the substrate is smaller as compared with a conventional LDC structure. In general, the speed of a device is proportional to the product obtained by multiplying together a load capacitance and an inverse of a current value of the device. Accordingly, in the case of applying the present invention to a circuit such as a NAND type CMOS circuit in which a voltage is applied to a region between the source and the substrate, the speed of the device is not decreased. On the other hand, the power consumption of a device is proportional to the product obtained by multiplying together a load capacitance and the square of an applied voltage. Consequently, according to the present invention, a semiconductor device which can be operated at a low power consumption is realized.

MOS type semiconductor device having an impurity diffusion layer

A complementary semiconductor device which includes: a semiconductor substrate having a principal surface, with a first region doped with an impurity of a first conductivity type and a second region doped with an impurity of a second conductivity type; a first MOS transistor provided on the second region; and a second MOS transistor provided on the first region. In such a complementary semiconductor device, at least one of the first MOS transistor and the second MOS transistor is an asymmetric MOS transistor of the same conductivity type as the conductivity type of the corresponding region which is either the first region or the second region. The asymmetric MOS transistor further includes an asymmetric impurity diffusion region having a nonuniform impurity concentration distribution in the channel region along a channel length direction such that an impurity concentration on a source side is set to be higher than an impurity concentration on a drain side, and an impurity concentration of a portion of the semiconductor substrate beneath the first source region is lower than the impurity concentration on the source side of the asymmetric impurity diffusion region.

Complementary semiconductor device and method for producing the same

MOS type semiconductor device having an impurity diffusion layer with a

Method for forming complementary MOS device having asymmetric region in

A MIS transistor has a semiconductor substrate of a first conduction type; a gate insulation film and a gate electrode which are selectively formed on the semiconductor substrate; an insulating film formed on the side surface of the gate electrode and on the semiconductor substrate; a first gate side wall layer provided on the upper surface and side surface of the insulating film and having a dielectric constant greater than that of the insulating film, the first gate side wall layer having a height smaller than that of the gate electrode; and a second gate side wall layer composed of an insulating film which covers the first gate side wall layer. This MIS transistor can be produced by a known LSI production technique employing self-alignment, without increasing the number of the steps of the process.

MIS transistor with gate sidewall insulating layer

An unsymmetrical MOS device is disclosed which includes a semiconductor layer of a first conductive type having a surface having a first area and a second area which is offset from the first area; a gate insulator layer located on the first area of the surface of the semiconductor layer; a gate electrode located on the gate insulator layer; and a source region of a second conductive type and a drain region of the second conductive type each located in the semiconductor layer below the second area of the surface. The electric resistance of an area between the first area of the surface and the surface of the source region is smaller than the electric resistance of an area between the first area of the surface and the surface of the drain region.

Unsymmetrical MOS device having a gate insulator area offset from the

An object of the subject invention is to offer a MOS semiconductor device capable of suppressing hot carrier degradation, improving driving capabilities and also enabling miniaturization to the submicron region and smaller; and methods for its fabrication. By forming the gate electrode 5 through the medium of gate oxide film 4 on one main surface of the first conductivity type semiconductor substrate 1 between the second conductivity type low concentration diffusion layers 3, the effective channel length is made roughly equal to the gate length, and miniaturization to the submicron region and smaller is accomplished. Also, by forming the second conductivity type diffusion layer 7A on the sides of the gate electrode 5 through the medium of the thin insulating film 6 to be above the low concentration diffusion layer 3 and further contacting the low concentration diffusion layer 3, the high electrical field within the low concentration diffusion layer 3 is sufficiently ameliorated, generation of hot carriers is suppressed, and resistance to degradation is improved. Moreover, by controlling the high resistance second conductivity typetype diffusion layer 7 A at the sides of the gate electrode 5, the source resistance is decreased and driving capabilities are improved. At the same time the contact region of the source-drain electrode is miniaturized.

MOS transistor and its fabricating method

An MOS type semiconductor device comprises a semiconductor substrate including a p-type region doped with p-type impurities and having a surface and an MOS transistor formed in the p-type region, the MOS transistor including: an n-type source region formed in the p-type region; an n-type drain region formed in the p-type region and separated from the n-type source region by a predetermined distance; a channel region formed in the p-type region and located between the n-type source and drain regions; a pair of n-type impurity diffusion regions formed on both sides of the channel region and having an impurity concentration lower than that of the n-type source region; a gate insulating film formed on the surface of the semiconductor substrate, the gate insulating film directly covering the channel region and the pair of n-type impurity diffusion regions; a gate electrode formed on the gate insulating film; and side walls formed on the sides of the gate electrode, wherein each of the side walls has a bottom portion extending along the surface of the semiconductor substrate from each side of the gate electrode, and each of the n-type source and drain regions has a first portion covered with the bottom portion of the side wall and a second portion not covered with the bottom portion, a thickness of the first portion being smaller than that of the second portion. A method for fabricating such an MOS type semiconductor device is also provided.

MOS type semiconductor device having a low concentration impurity

LDD FET with polysilicon sidewalls

A MIS transistor, has a semiconductor substrate of a first conduction type; a gate insulation film and a gate electrode which are selectively formed on the semiconductor substrate; an insulating film formed on the side surface of the gate electrode and on the semiconductor substrate; a first gate side wall layer provided on the upper surface and side surface of the insulating film and having a dielectric constant greater than that of the insulating film, the first gate side wall layer having a height smaller than that of the gate electrode; and a second gate side wall layer composed of an insulating film which covers the first gate side wall layer. This MIS transistor can be produced by a known LSI production technique employing self-alignment, without increasing the number of the steps of the process.

Growing community of inventors

Osaka, Japan

Akira Hiroki