The 21-year-old computer engineering student beat hundreds of international contestants to win a bronze medal, his university announced on Tuesday.
The contest, which attracted 370 contestants from Armenia, Argentina, Brazil, Egypt, Peru, Russia, Serbia, UAE, Ukraine, and Vietnam, was forced online and delayed from December due to the Covid-19 outbreak.
"I was very happy to hear the result. The first people I called were my parents living in rural Binh Dinh Province," he said.
Hieu first knew about AMO more than a year ago and found it very interesting. He spent a year learning about microelectronics, including digital circuits, theory designs and object-oriented programming.
Last September he took a national competition and beat 110 other candidates to the right to represent Vietnam in the global event, where candidates got three hours to answer 18 questions.
He said the hardest were questions related to integrated circuit design, which he has not learned in college yet.
"Besides the correct answer, candidates also needed to provide scientific and reasonable solutions to the jury."
He got 12 questions right.
The annual contest for engineers and technology students under 30 is organized by Synopsys, which specializes in semiconductor design software.
A Serbian student won the first prize while second prize went to Armenia. Hieu shared the third prize with two others from Armenia and Brazil.