THREE-DIMENSIONAL MEMORY DEVICE CONTAINING A CHANNEL CONNECTION STRAP AND METHOD FOR MAKING THE SAME

A three-dimensional memory device includes an alternating stack of insulating layers and electrically conductive layers located over a substrate, a memory opening extending through the alternating sack, and a memory opening fill structure located within the memory opening. The memory opening fill structure includes a pedestal channel portion, a memory film overlying the pedestal channel portion, a vertical semiconductor channel located inside the memory film, and a channel connection strap that extends through an opening of the memory film and contacting the pedestal channel portion and the vertical semiconductor channel. The channel connection strap has a topmost surface located below a horizontal plane including a top surface of the vertical semiconductor channel. The channel connection strap portion may be formed by a selective semiconductor growth from physically exposed semiconductor surfaces, and may provide enhanced electrical connection between the pedestal channel portion and the vertical semiconductor channel.