International Business Machines Corporation

Qiging Ouyang

Alfred Grill

Kern Rim

Jack Oon Chu

Herbert Lei Ho

Meikei Ieong

Steven John Koester

Jeremy Daniel Schaub

Christopher D Sheraw

Mahender Kumar

Michael D Steigerwalt

Paul A Papworth

Gabriel Konrad Dehlinger

The present invention provides a 'subcollector-less' silicon-on-insulator (SOI) bipolar junction transistor (BJT) that has no impurity-doped subcollector. Instead, the inventive vertical SOI BJT uses a back gate-induced, majority carrier accumulation layer as the subcollector when it operates. The SOI substrate is biased such that the accumulation layer is formed at the bottom of the first semiconductor layer. The advantage of such a device is its CMOS-like process. Therefore, the integration scheme can be simplified and the manufacturing cost can be significantly reduced. The present invention also provides a method of fabricating BJTs on selected areas of a very thin BOX using a conventional SOI starting wafer with a thick BOX. The reduced BOX thickness underneath the bipolar devices allows for a significantly reduced substrate bias compatible with the CMOS to be applied while maintaining the advantages of a thick BOX underneath the CMOS. A back-gated CMOS device is also provided.

Vertical bipolar transistor with a majority carrier accumulation layer as a subcollector for SOI BiCMOS with reduced buried oxide thickness for low-substrate bias operation

The present invention provides CMOS structures including at least one strained pFET that is located on a rotated semiconductor substrate to improve the device performance. Specifically, the present invention utilizes a Si-containing semiconductor substrate having a (100) crystal orientation in which the substrate is rotated by about 45&#xb0; such that the CMOS device channels are located along the &#x3c;100&#x3e; direction. Strain can be induced upon the CMOS structure including at least a pFET and optionally an nFET, particularly the channels, by forming a stressed liner about the FET, by forming embedded stressed wells in the substrate, or by utilizing a combination of embedded stressed wells and a stressed liner. The present invention also provides methods for fabricating the aforesaid semiconductor structures.

Strained complementary metal oxide semiconductor (CMOS) on rotated wafers and methods thereof

The invention addresses the problem of creating a high-speed, high-efficiency photodetector that is compatible with Si CMOS technology. The structure consists of a Ge absorbing layer on a thin SOI substrate, and utilizes isolation regions, alternating n- and p-type contacts, and low-resistance surface electrodes. The device achieves high bandwidth by utilizing a buried insulating layer to isolate carriers generated in the underlying substrate, high quantum efficiency over a broad spectrum by utilizing a Ge absorbing layer, low voltage operation by utilizing thin a absorbing layer and narrow electrode spacings, and compatibility with CMOS devices by virtue of its planar structure and use of a group IV absorbing material. The method for fabricating the photodetector uses direct growth of Ge on thin SOI or an epitaxial oxide, and subsequent thermal annealing to achieve a high-quality absorbing layer. This method limits the amount of Si available for interdiffusion, thereby allowing the Ge layer to be annealed without causing substantial dilution of the Ge layer by the underlying Si.

Structure for and method of fabricating a high-speed CMOS-compatible Ge-on-insulator photodetector

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Qiging Ouyang