Abstract: A clock signal generation apparatus for generating a reference clock signal for outputting data in synchronization with an external clock signal from a semiconductor memory device, including: a clock signal generation unit for receiving an internal clock signal to generate the reference clock signal according to a control signal; and a control unit for generating the control signal based on a read command, a write command and an external address.

Abstract: A semiconductor memory device includes a CAS latency mode detecting means for outputting a CAS latency control signal in response to a CAS latency mode; and an auto-precharge control means for controlling timing of an auto-precharge operation in response to the CAS latency control signal.

Abstract: A semiconductor memory device includes a first first-type well including a first cell array for storing a data to apply the data to one of a first bit line and a first bit line bar, and a first precharge MOS transistor having a second-type channel for equalizing voltage levels of the first bit line and the first bit line bar; a first second-type well including a first sense amplifying MOS transistor having a first-type channel for sensing and amplifying the signal difference between the first bit line and the first bit line bar, and a first connection MOS transistor; and a second first-type well including a second sense amplifying MOS transistor having a second-type channel for sensing and amplifying the signal difference between the first bit line and the first bit line bar.

Abstract: A method of manufacturing a semiconductor device having the steps of forming an insulating layer on a silicon substrate, forming a contact hole on the insulating layer, forming a selective silicon layer in the contact hole, and forming a selective conductive plug on the selective silicon layer.

Abstract: An on-die termination circuit is capable of increasing a resolution without enlargement of a chip or a layout size. The on-die termination circuit includes a control means, a termination resistance supply means, a code signal generating means. The control means sequentially generates a plurality of control signals in a response to a driving signal. The termination resistance supply means supplies a termination resistance in response to a coarse code signal having a plurality of bits and a fine code signal having a plurality of bits. The code signal generating means controls the fine code signal and the coarse code signal in response to the plurality of the control signals in order that the termination resistance has a level which is correspondent to an input resistance.