Investigation of Electric Field Induced Ion Migration in Semiconductor Encapsulation Materials without the Interference of Electron Conductivity

Abstract

Ion migration can cause severe damage to high power semiconductor devices. One of the main sources of mobile ions is the encapsulation material such as molding compounds. Within this work a method will be described to evaluate the risk of field induced ion migration of different molding compounds depending on the temperature and field strength. This method allows the qualitative and quantitative determination of ion mobility in molding compounds, without the interference of electron conductivity.

A Chip Integrity Monitor for Evaluating Moisture/Ion Ingress in mm-Sized Single-Chip Implants

“…For the 0.18 µm process used, the distance between the metal plates (L) is 1 µm and for the chosen sensor implementation that will be presented in Section III, the area is 58.17 µm 2 . The value of ρ depends on the manufacturing process, and its value ranges between 10 12 Ωm [37] and 10 16 Ωm [24]. Based on these values, the ILD resistance of the sensor is expected to be in the peta-ohm to exa-ohm [10 15 -10 18 ] range.…”

“…In wet ionic environments like the human body, failure of electronics can occur due to the ingress of moisture and ions through the packaging. For silicon integrated circuits, such ingress through the top passivation and interlayer dielectrics (ILD) would result in parameter changes in the passive (capacitive/resistive) and active (MOS transistor) components, as well as shorts and/or hard opens that would eventually lead to device failure [22], [23], [24]. Conventionally, AIMDs such as pacemakers and cochlear implants have relied on titanium (Ti) packages for protecting the inside electronics against the surrounding fluids.…”

Pathways for Alkali Ion Transport in Mold Compounds

“…Samples.-The molding compound (MCP) used for this study contained ortho-cresol novolack epoxy resign, a phenolic hardener, a metal oxide as flame retardant and 82 wt% SiO 2 as filler material (sample MCP 3 from Ref. 24). The sample with a size of 10 × 10 × 0.5 mm was glued onto a copper electrode employing a silver containing heat conducting glue (Polytech EC 101).…”

“…As one aspect of electric conductivity, it is known that molding compounds can show a finite ionic conductivity. [23][24][25] The ion migration can constitute the risk that ions from the molding compound can move into the sensitive parts of the microelectronic device and influence its operation or can even destroy it.…”

“…Recently, the sodium conductivity of mold compounds has been successfully described using a novel method, employing an amalgam electrode setup. 24,25 An alternative to this method is the CAIT technique. [30][31][32][33][34] This method employs an ion beam that is directed onto the sample surface.…”