| 摘要 |
A method for forming a bulb type recess gate is provided to minimize attack of a substrate caused by an etching process by forming a bulb type groove using a silicon epitaxial layer. A groove is formed by etching a gate forming region of a substrate(100). An insulating layer is formed at the bottom and the sidewalls of the groove. A silicon epitaxial layer(120) is grown, so that the groove has a bulb shape. The insulating layer is removed. A gate insulating layer(122) is formed on the bulb type groove. A gate conduction layer(124) and a hard mask layer are formed on the gate insulating layer to entirely fill the groove. A bulb type recess gate is then formed by etching the hard mask layer, the gate conduction layer and the gate insulating layer.
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