Abstract: A three-dimensional source contact structure and its fabrication process method thereof are applicable to a power device, in which an inter-layer dielectric is deposited thereon. A lithography process is applied for forming a first and second dielectric layer. A spacer is respectively provided on opposite sidewalls of the first and second dielectric layer. And a shallow trench process is sequentially performed along the opposite surfaces of the spacers. The spacers are removed after the shallow trench process is complete for exposing a first and a second metal-source surface contact region. The present invention achieves in increasing horizontal surface contact and longitudinal vertical contact when depositing a source contact metal, thereby a step-like three-dimensional source contact structure can be formed. By employing the present invention, it enhances to reduce cell pitch effectively and can be widely applied to various power devices having MOSFET structure thereof.

Abstract: A three-dimensional source contact structure and fabrication process method thereof are provided. A lithography process and shallow trench process are sequentially performed to form a metal contact window in a power device. A source heavily doped area is divided by the metal contact window into a first and second heavily doped region. A lateral etching process is applied to an inter-layer dielectric to form a first and a second dielectric layer, each of which is in a trapezoid shape. Meanwhile, a first and a second metal-source surface contact regions are exposed. A longitudinal surface exposed by the shallow trench process is beneficial to increase vertical contact when depositing a source contact metal, thereby a step-like three-dimensional source contact structure can be formed. The present invention achieves in reducing cell pitch effectively and can be widely applied to various power devices having MOSFET structure thereof.

Abstract: A process method for fabricating a three-dimensional source contact structure is provided, which is applicable to form a step-like three-dimensional source contact structure in a MOSFET of a power device. The proposed method sequentially adopts a lithography process and a shallow trench process to form a metal contact window. And a lateral etching process, or spacers which will be removed eventually, can be alternatively provided for increasing horizontal surface contact when depositing a source contact metal. Meanwhile, a longitudinal surface exposed by the shallow trench process is also beneficial to increase vertical contact when depositing the source contact metal. As a result, a step-like three-dimensional source contact structure can be formed by employing the present invention. It is believed that the present invention achieves in reducing cell pitch effectively and can be widely applied to various power devices having MOSFET structure thereof.