Patent ID: 8221045

Claim:
A semiconductor manufacturing apparatus, comprising: a first boat and a second boat having a plurality of first slots and a plurality of second slots, respectively, and disposed such that the first slots and the second slots alternate each other, the first boat mounting a plurality of first wafers in the first slots to support front faces of the first wafers in a predetermined direction, the second boat mounting a plurality of second wafers in the second slots to support back faces of the second wafers in the predetermined direction; a reaction tube having an opening and containing the first and second boats mounting the first and second wafers; a plate sealing up the opening of the reaction tube containing the first boat and the second boat; a reaction gas supplier supplying reaction gas into the sealed reaction tube for a predetermined process, and wherein each of the first slots of the first boat having the first wafers mounted thereon is at a different height of the semiconductor manufacturing apparatus than a height of each of the second slots of the second boat having the second wafers mounted thereon during the predetermined process; and a reaction gas exhauster exhausting the reaction gas from the reaction tube to the external of the reaction tube after the predetermined process.