I subscribe to the notion that less wood in contact with anything close to the ground, the better. This includes anchors for deck stairs.
The pressure treated wood kicker often used to anchor deck stairs invites trouble unless you live in a particularly arid environment, like Arizona or New Mexico. In most places, water, leaves, and debris make nice homes for creepy critters, store moisture, and undermine the integrity of wood. For deck stair construction, it makes sense to apply flashing in some appropriate areas, establish stand-offs between wood and wet, and anchor using threaded rod and angle irons for the stringers.
It’s tempting to simply flash the bottom of the stair stringer, but flashing often allows some moisture behind it. Instead, put it on and then screw in the #14 screws to give you a standoff. In tropical locations, for rods and angles, stainless steel is the only way to go, but in a lot of places, galvanized is fine. Also flash the top of the stringer where you install the tread.
The top of the stringer should be solidly anchored to the rim joist using a joist hander and lagged, like this:
Deck Stringer Connection-Rim Joist
Bolt-Through on the Joist
Here is the completed stringer connection. Note that the stringers have stiffeners fastened with screws.
Completed Stringer w/Stiffeners
Where the stringers make contact with the footing, make sure you separate wood and wet by using two products – peel and stick flashing at the bottom (not shown), and then install 4-5 #14 stainless screws ( short screws 1 – 1 1/2″) to provide a standoff for the stringer, like this:
Standoff with base screws
The foot of the stringer needs to be attached to the footing. Interior stairs typically have a kicker installed, but exterior needs to have thought put into how to avoid rot, so I prefer an all metal solution with steel angles and rod bolts like this.
Angle and steel rod anchors
Again, consult your local building code and the Simpson Strong-Tie Connector literature/website for appropriate use of connectors and anchors. Simpson has a useful deck center code guide that frequently receives updates.