Semiconductor device having one or more titanium interlayers and method of making the same

A method for fabricating semiconductor devices, the method comprising the steps of:

• providing a semiconductor wafer comprising
• a substrate layer, the substrate layer being a heavily doped first conductivity type silicon substrate layer;
• an epitaxial layer directly attached to the substrate layer, the epitaxial layer being a lightly doped first conductivity type silicon epitaxial layer;
• a dielectric layer directly attached to the epitaxial layer;
• depositing a first aluminum layer on the semiconductor wafer at a first predetermined temperature in a range from 350° C. to 500° C.;
• depositing a first titanium interlayer on the first aluminum layer at a second predetermined temperature in a range from 100° C. to 200° C.;
• depositing a second aluminum layer on the first titanium interlayer at a third predetermined temperature in the range from 350° C. to 500° C.;
• applying an etching process to expose a portion of the dielectric layer;
• and
• applying a singulation process forming a plurality of separated semiconductor devices;
• wherein the epitaxial layer comprises
• a plurality of source regions;
• and
• a plurality of trenches filled with a same insulated gate material;
• wherein the first aluminum layer directly contacts the plurality of source regions;
• wherein the epitaxial layer is made of a silicon material;
• and
• wherein a separation trench formed by the etching process divides the first aluminum layer, the first titanium interlayer and the second aluminum layer into a first portion in a termination area and a second portion in an active area.

A method for fabricating semiconductor devices, the method comprising the steps of:

• providing a semiconductor wafer comprising
• a substrate layer, the substrate layer being a heavily doped first conductivity type silicon substrate layer;
• an epitaxial layer directly attached to the substrate layer, the epitaxial layer being a lightly doped first conductivity type silicon epitaxial layer;
• a dielectric layer directly attached to the epitaxial layer;
• depositing a first aluminum layer on the semiconductor wafer;
• depositing a first titanium interlayer on the first aluminum layer;
• depositing a second aluminum layer on the first titanium interlayer;
• applying an etching process to expose a portion of the dielectric layer;
• and
• applying a singulation process forming a plurality of separated semiconductor devices;
• wherein a thickness of the first titanium interlayer is in a range from ten angstroms to five hundred angstroms;
• and
• wherein a thickness of the first aluminum layer and a thickness of the second aluminum layer are in a range from one micron to four microns.