Abstract: Three-dimensional (3D) memory devices and fabricating methods are disclosed. A disclosed 3D memory device includes a first semiconductor structure. The first semiconductor structure includes an array of first-type through stack structures in a first region and an array of second-type through stack structures in a second region, and a slit structure separating the array of first-type through stack structures from the array of second-type through stack structures. The 3D memory device further includes a second semiconductor structure. The second semiconductor structure includes a first periphery circuit and a second periphery circuit at different levels. The second semiconductor structure and the first semiconductor structure are bonded together, such that the first periphery circuit is located between the second periphery circuit and the first semiconductor structure.

Abstract: Aspects of the disclosure provide a semiconductor device and a method to manufacture the semiconductor device. A channel hole is formed in a stack including alternating first layers and second layers. The stack is formed over a substrate of the semiconductor device. A gate dielectric layer and a channel layer are sequentially formed in the channel hole. Laser annealing is performed on the channel layer using laser light. An incidence angle of the laser light on an upper surface of the channel layer causes a total internal reflection to occur at an interface between the channel layer and the gate dielectric layer and an interface between the channel layer and an insulating layer that is adjacent to the channel layer.