To stop from navigating simply this code works!
$(document).on("keydown", function (event) {        
   if (event.keyCode === 8) {
      event.preventDefault();
    }
  });
But that will even also happen for input fields type text/textarea. 
So to restrict it for those fields, you may use
$(document).on("keydown", function (event) {
  if (event.which === 8 && !$(event.target).is("input, textarea")) {
   event.preventDefault();
  }
});
In my case where I had a text field for calendar and whenever I'd click on that calendar, Select date and press backspace it'd navigate back to previous page. To prevent it for that field only I simply used
$('#myField').on("keydown", function (event) {
  if (event.keyCode === 8 || event.which === 8) { 
   event.preventDefault(); 
  } 
});
I thought to mention for some to help ;-)