Implant devices, leakage

Prior to the final trench filling, a trench implantation (boron for P-type substrates) is performed. This is to ensure that the P-type substrate does not invert during subsequent processing and cause device-to-device leakages. The implant is directed vertically into the trench. Under these conditions the trench sidewall oxide acts as an efficient mask, while the implant in the bottom can reach into the substrate and form a P+ region. The remaining SiC film, which served as the RIE mask, also acts as an implant mask at the wafer surface. The implant energy and dose are adjusted for the thermal oxide thickness. 

Leakage. By far the majority of implanted electronic devices fail due to mechanisms of the second type (i.e. leakage). In a poorly encapsulated implant, this failure mode can cause rapid deterioration in a matter of days, hours, or even minutes. As the size of the implant designs are reduced, the risk of this type of failure is greatly Increased because due to the small dimensions involved, the time for fluid entry into the package becomes very short. 

The high reliability and the complete absence of faults such as electrolyte leakage or gas generation make the lithium-iodine solid state battery a particularly suitable device for powering implanted electronic devices, and it is now widely used in the cardiac pacemaker industry. The design and construction of Medtronic Inc, pacemaker batteries are shown in Fig. 9.12. A typical unit, such as the Enertec Alpha 33 , has dimensions of 33.4 mm X 27.4 mm X 7.9 mm, giving a total volume of 6.0 cm3 and a mass of 22 g. The cell has a completely welded construction and uses a specialized... 

The hydrogels were able to prevent drug leakage to a common conservation liquid for SCLs and to sustain drug delivery in lacrimal fluid for 2 weeks. The hydrogels with pendant pCDs are particularly useful for the development of cytocompatible medicated implants or biomedical devices, such as drug-loaded SCLs. 

The current situation with regard to silicone breast implants is discussed, with reference to claims that women have suffered physical injury from deterioration of, or leakage from, the devices. Legal and scientific questions and causal questions are briefly considered. 1 ref. 

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