A boom in Korea's semiconductor exports has strengthened the won, pushing it to its highest level against the Japanese yen in 18 years and 9 months, analysts said Wednesday. According to Hana Bank, the won-yen exchange rate fell as low as 844.16 won per 100 yen in intraday trading Wednesday, its lowest level since January 2008, when it stood at 837.58 won. The rate had hovered between 930 and 950 won per 100 yen in early July before falling sharply over the past three months. The yen is not traded directly in Seoul's foreign exchange market. Instead, banks calculate the won-yen exchange rate indirectly using each currency's exchange rate against the U.S. dollar. The won and the yen have moved in sharply different directions since July, a rare divergence between two currencies whose movements have historically reflected "significant overlap in the two countries' export structures," according to Ashok Bhundia, deputy chief economist at the Institute of International Finance. Analysts say the biggest driver of the Korean won's strength has been semiconductors. Robust chip exports have boost