Abstract: It is an object to provide a method of etching which enables measurement control of the micro width of a magnetic layer while shortening the time required for the etching procedure. An inorganic insulating film made of alumina which is the same material as the write gap layer is formed on a top pole layer by, for example, sputtering method. A photoresist film (first mask) is formed on the inorganic insulating film by photolithography. Next, an inorganic insulating mask (second mask) is formed by selectively etching the inorganic insulating film by reactive ion etching (RIE) using gas etchant such as CF4 (carbon ride), BCl3(boron trichloride), Cl2 (chlorine), SF6 (sulfur hexafluoride) and so on using the photoresist film as a mask. The top layer is selectively removed by, for example, ion milling with Ar (argon) using the inorganic insulating mask.

Abstract: In accordance with the present invention, during a polysilicon etch back, a controlled amount of oxygen (O2) is added to the plasma generation feed gases, to reduce pitting of the etched back polysilicon surface. The plasma etchant is generated from a plasma source gas comprising: (i) at least one fluorine-containing gas, and (ii) oxygen. The invention may be practiced in any of a number of apparatus adapted to expose polysilicon to a plasma etchant. One preferred apparatus is a decoupled plasma source (DPS™, Applied Materials, Santa Clara, Calif.) etching system. Another preferred apparatus is a magnetically enhanced plasma (MXP™, Applied Materials, Santa Clara, Calif.) etching system.