摘要:
The invention includes methods of fabricating a bipolar transistor that adds a silicon germanium (SiGe) layer or a third insulator layer of, e.g., high pressure oxide (HIPOX), atop an emitter cap adjacent the intrinsic base prior to forming a link-up layer. This addition allows for removal of the link-up layer using wet etch chemistries to remove the excess SiGe or third insulator layer formed atop the emitter cap without using oxidation. In this case, an oxide section (formed by deposition of an oxide or segregation of the above-mentioned HIPOX layer) and nitride spacer can be used to form the emitter-base isolation. The invention results in lower thermal cycle, lower stress levels, and more control over the emitter cap layer thickness, which are drawbacks of the first embodiment. The invention also includes the resulting bipolar transistor structure.
摘要:
The invention includes methods of fabricating a bipolar transistor that adds a silicon germanium (SiGe) layer or a third insulator layer of, e.g., high pressure oxide (HIPOX), atop an emitter cap adjacent the intrinsic base prior to forming a link-up layer. This addition allows for removal of the link-up layer using wet etch chemistries to remove the excess SiGe or third insulator layer formed atop the emitter cap without using oxidation. In this case, an oxide section (formed by deposition of an oxide or segregation of the above-mentioned HIPOX layer) and nitride spacer can be used to form the emitter-base isolation. The invention results in lower thermal cycle, lower stress levels, and more control over the emitter cap layer thickness, which are drawbacks of the first embodiment. The invention also includes the resulting bipolar transistor structure.
摘要:
Methods for forming a spacer (44) for a first structure (24, 124), such as a gate structure of a FinFET, and at most a portion of a second structure (14), such as a fin, without detrimentally altering the second structure. The methods generate a first structure (24) having a top portion (30, 130) that overhangs an electrically conductive lower portion (32, 132) and a spacer (44) under the overhang (40, 140). The overhang (40, 140) may be removed after spacer processing. Relative to a FinFET, the overhang protects parts of the fin (14) such as regions adjacent and under the gate structure (24, 124), and allows for exposing sidewalls of the fin (14) to other processing such as selective silicon growth and implantation. As a result, the methods allow sizing of the fin (14) and construction of the gate structure (24, 124) and spacer without detrimentally altering (e.g., eroding by forming a spacer thereon) the fin (14) during spacer processing. A FinFET (100) including a gate structure (24, 124) and spacer (44) is also disclosed.