The KOSPI index is displayed at a dealing room of Hana Bank in Seoul, Thursday. Yonhap 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 program trading for five minutes.A buy-side sidecar is triggered when the KOSPI 200 Futures index increases 5 percent or more for at least one minute.Overnight, Wall Street closed mixed on concerns about overvaluation of artificial intelligence (AI)-related shares.The Dow Jones Industrial Average rose 0.35 percent, while the S&P 500 lost 0.1 percent and the Nasdaq composite retreated 0.43 percent.However, investor sentiment was boosted after Micron released its quarterly report following the market closure as its results and forecast both exceeded expectations.In Seoul, market bellwether Samsung Electronics jumped 4.99 percent and chip giant SK hynix soared 9.88 percent.Samsung Electro-Mechanics, an electronic components manufacturing affiliate of Samsung Electronics, advanced 2.24 percent and SK Square, the parent of SK hynix, vaulted 8.56 percent.Top carmaker Hyundai Motor climbed 1.18 percent and its auto parts affiliate Hyundai Mobis gained 2.16 percent.The Korean won was trading at 1,547.95 won against the U.S. dollar, down 6.15 won from the previous session, as of 9:15 a.m.