Korean stocks opened sharply higher Thursday, driven by gains in semiconductor shares stemming from a stronger-than-expected earnings report by U.S. memory chipmaker Micron Technology. After going 2.74 percent higher, the benchmark Korea Composite Stock Price Index (KOSPI) further added 474.93 points, or 5.61 percent, to 8,945.95 as of 9:15 a.m. The steep rise triggered Seoul's bourse operator to issue a buy-side sidecar at 9:07 a.m., halting pr…