Cajetan Wagner

Automotive 130 nm smart-power-technology including embedded flash functionality

In this paper a 130 nm BCD technology platform is presented. The process offers logic-devices, flash-devices and high voltage devices with rated voltages up to 60 V. There are HV analog devices with variable channel length and HV power devices with low on-resistances. To ensure the safe operation of the power devices, a superior robustness against high energetic pulses of different length and repetitions could be achieved. The isolation of the different voltage stages is ensured by deep trenches and highly doped buried layers.

A low-cost fully self-aligned SiGe BiCMOS technology using selective epitaxy and a lateral quasi-single-poly integration concept

We present a low-cost concept for a self-aligned SiGe heterojunction bipolar transistor (HBT). In conventional double-poly HBTs, the base link is formed by use of a sacrificial layer to grow the SiGe epitaxy between an external base polysilicon and the silicon substrate, resulting in a vertical base link. In this concept, the SiGe epitaxy is laterally connected to the extrinsic base poly forming a short and fully self-aligned base link. While strongly reducing process complexity, this concept maintains a minimal link resistance between the internal and the external base. We demonstrate the integration of this HBT with balanced dc and ac performance in a 0.25-/spl mu/m bipolar complementary metal-oxide-semiconductor technology, featuring all passive devices necessary for RF design. The bipolar multitransistor yield shows similar values compared to our conventional double-poly integration concept.

Visualizing the doping profile of a silicon germanium HBT with polysilicon emitter using electron holography

Modern bipolar transistors use polysilicon emitters and an epitaxial grown silicon germanium (SiGe) base. For device optimization, both the SiGe base and the region of the diffused emitter is of special interest. In this paper, electron holography is applied to visualize and directly measure the two-dimensional distribution of the local potential in a high-performance SiGe heterojunction bipolar transistor. Special emphasis is put on investigating the region of the emitter diffused into the epitaxially grown base layer. In addition, we investigate the self-aligned base-link construction. We compare electron holographic measurements of the whole transistor to secondary ion mass spectrometric (SIMS) data and discuss the results.

Reliability degradation of MOS transistors originated from plasma process-induced charging of circuit blocks and detected with fWLR methods

The effect of plasma process induced charging of remote circuit blocks and consequently the reliability damage on a single MOS transistor which is connected to such a circuit block is demonstrated for the first time. Traditional methods of characterizing gate electrode antennas do not cover this topic. A new product relevant plasma-induced damage test structure type is introduced as well as a new definition of the antenna ratio to describe the damage potential of a circuit block. This investigation is carried out for a standard 130nm bulk-Si technology with a deep trench process.

Electron holography for visualisation of different doped areas in silicon-germanium heterojunction bipolar transistors

A bipolar transistor with a silicon-germanium base (HBT) was prepared by the focused ion beam technique for TEM-cross-sectioning, taking into account the special requirements of electron holography. A line plot from the phase image through the functional region includes the influences of different dopant content as well as different germanium concentrations on the mean inner potential. Interpretation of the superimposed contributions to the phase shift succeeds by using additional information from SIMS data.