KLA-Tencor is hard-core when it comes to hunting down flaws in chips. The company -- one of the world's largest makers of semiconductor equipment -- offers yield management systems that monitor and analyze wafers at various stages of chip production, inspecting reticles (which make circuit patterns) and measuring crucial microscopic layers. The systems' feedback allows flaws to be corrected before they can ruin the costly wafers. KLA-Tencor has long dominated the market for equipment that inspects semiconductor photomasks and reticles. The company earns almost 80% of sales outside the US; its two largest customers, leading global semiconductor manufacturers Intel and TSMC, together account for more than 20% of sales.