A second blocking layer formed of a Si:C or a Si:N on {HEAD ~ the first blocking layer} contains {TAIL ~ 1×10 8 to 1×10 4 atomic %} 
A second blocking layer formed of a Si : C or a Si : N on { HEAD ~ the first blocking layer } contains { TAIL ~ 1×10 8 to 1×10 4 atomic % }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL