CONTACT STRUCTURE HAVING CONDUCTIVE OXIDE, FERROELECTRIC RANDOM ACCESS MEMORY DEVICE EMPLOYING THE SAME AND METHODS OF FABRICATING THE SAME

摘要

A contact structure having a conductive oxide layer, a ferroelectric memory device employing the same, and manufacturing methods thereof are provided to prevent the generation of a minute crack between a contact plug and a lower electrode by using a conductive protection pattern made of the conductive oxide layer. An interlayer dielectric(131) is provided on a semiconductor substrate. A contact plug(141) passes through the interlayer dielectric and is comprised of a metal plug(135) and a buffer plug(140) which are sequentially laminated. A conductive protection pattern(145a) is formed with a conductive oxide layer and covers the contact plug. A lower electrode(156a), a ferroelectric pattern(157a), and an upper electrode(159a) are sequentially laminated on the conductive protection pattern. An insulating protective layer(165) covers the lower electrode, the ferroelectric pattern, and the upper electrode. The metal plug is made of tungsten. The buffer plug is made of metal nitride or conductive oxide.