The 17-year-old singer received the lowest number of viewer votes after performing Avril Lavigne's 'Girlfriend' and Dido's 'White Flag' in the latest live round.
Vickers's rival act and close friend Eoghan Quigg burst into tears after the result was announced, while her mentor Cheryl Cole also appeared to be emotional.
Speaking to show host Dermot O'Leary, Vickers revealed: "I've absolutely loved it. I've had the time of my life and I want to thank everyone so much - everyone that's looked after me. Cheryl, thank you."
Asked to name her favourite moment of the competition, she replied: "All of it. I've met some amazing people like little Eoghan and I'm going to remember [them] for the rest of my life."
Cole added: "I don't think this is the last we'll see of her. I'm really proud of her and I've absolutely loved every minute of working with her."
Quigg, Alexandra Burke and boyband JLS will now compete for the £1 million recording contract in next week's final.