<p>We have developed ion doping system named iG8 for 8th-generation (Gen. 8) glass, which can extract &gt; 2200 mm high ion beams, larger than glass height. Although iG8 basic concept is the same as Gen. 5 and 6 doping systems, iG5 and iG6, we have investigated and developed new three component technologies: the large size beam unit and scan unit for Gen. 8 substrate, the machine downtime reduction, and system unitization, in response to the industry requirements. As a result, iG8 has the same ion implantation capabilities as the iG6 even on the Gen. 8 substrates, more than 3 times cathode lifetime with reduced production downtime, and allows independent modification of each unit for enhancing functionality.</p> Graphical abstract <p>Beam current densities as a function of measurement position of iG6 and iG8, where ion species is boron (B+), the ion energy 30 keV, and average beam current density 425 μA/cm for both implanters. Although the number of Faraday cups in iG8 is 90 which is 1.5 times the amount of the iG6, iG8 beam current uniformity is within 3 %, same as the iG6 beam distribution. The result exhibits one of the good performance of beam control techniques even though the large-sized ion beam as never before</p> <p></p>