Since 2009 the Institute of High Energy Physics (HEPHY) in Vienna is developing a production process for planar silicon strip sensors on 6-in. wafers together with the semiconductor manufacturer Infineon Technologies. Four runs with several batches of wafers, each comprising six different sensors, were manufactured and characterized. A brief summary of the recently completed 6-in. campaign is given. Milestones in sensor development as well as techniques to improve the sensor quality are discussed. Particular emphasis is placed on a failure causing areas of defective strips which accompanied the whole campaign. Beam tests at different irradiation facilities were conducted to validate the key capability of particle detection. Another major aspect is to prove the radiation hardness of sensors produced by Infineon. Therefore, neutron irradiation studies were performed.