Abstract:
Apparatus for etching a patterned layer of a noble metal such as platinum. The apparatus implements a process whereby exposed areas of the noble metal are first implanted with ions and are subsequently etched. Both the ion implantation step and the etching step occur sequentially in the same chamber in the presence of a plasma discharge. The apparatus uses either a dual output power supply or two distinct power supplies to sequentially supply a high power output required for the ion implantation step and a low power output required for the etching step. Multiple cycles of implantation followed by etching may be applied to achieve deep etching of thick layers. A programmed computer controls the process steps. A method of using the apparatus is also provided.
Abstract:
PROBLEM TO BE SOLVED: To provide an improved method of forming a vertical MOSFET structure. SOLUTION: A method of forming a semiconductor memory cell array structure comprises a process of providing a vertical MOSFET DRAM cell structure having a deposited gate conductor layer 22 planarized up to the top surface of a trench top oxide 24 on a silicon substrate, a process of forming a recess 39 in the gate conductor layer below the top surface of the silicon substrate, a process of forming doping pockets 46 in an array P well 32 by implanting N-type dopant species through the recess at an angle, a process of forming spacers 44 on the side wall of the recess by depositing an oxide layer in the recess and then etching the oxide layer, and a process of depositing a gate conductor material in the recess and then planarizing the gate conductor material up to the top surface of the trench top oxide.