Silicon wafer
1995
1995
1995
1995
1995
1995
1995
1995
1995
1995
1995
1995
circa 1950
circa 1950
circa 1950
circa 1950
circa 1950
1995
1995
1995
1995
1995
1995
1995
1995
circa 1950
circa 1950
circa 1960
circa 1950
circa 1950
circa 1950
circa 1960
circa 1950
circa 1950
circa 1950
circa 1950
circa 1950
circa 1950
1966
circa 1950
circa 1950
circa 1950
circa 1950
circa 1950
1965/66
circa 1950
circa 1950
circa 1950
circa 1970
circa 1972