Method for manufacturing a micro-electronic component having an electrically conductive tip of doped silicon

Method for manufacturing a micro-electronic component having an electrically conductive tip of doped silicon, comprising the steps of:

• applying a mask on a substrate of monocrystalline silicon, wherein said step of applying said mask includes:
• applying a first layer of a first insulator material onto said substrate;
• applying a second layer of an electrically conductive material onto said first layer;
• applying a third layer of a second insulator material onto said second layer;
• providing an opening in said mask so that a portion of a surface of said substrate is uncovered at said opening, said opening having a smaller cross section than an uncovered surface portion of said substrate at said opening, wherein said step of providing said opening includes:
• shaping said third layer by anisotropic etching to form said opening;
• selectively shaping said first layer by isotropic etching relative to said second layer and said third layer to uncover said surface of substrate, said selective shaping resulting in under-etching of said first layer under edges of said second layer;
• and
• simultaneously producing a tip of doped polysilicon on said uncovered surface portion of said substrate and depositing a doped silicon layer on a surface of said mask by molecular beam epitaxy of doped silicon while maintaining said opening intact, and retaining said mask structure with said doped silicon layer thereon on said substrate.