US 6,982,434 B2
Quantum-well memory device and method for making the same
Yen-Hao Smith, Hsinchu (Taiwan)
Assigned to Macronix International Co., Ltd., (Taiwan)
Filed on Apr. 23, 2004, as Appl. No. 10/831,431.
Prior Publication US 2005/0236613 A1, Oct. 27, 2005
Int. Cl. H01L 29/06 (2006.01)
U.S. Cl. 257—24 9 Claims
OG exemplary drawing
 
1. A quantum well memory device, comprising:
a substrate;
a bottom oxide layer having a first oxide property and extending a length between a first junction and a second junction;
a middle insulator layer having a second property that is more soluble to an acid etch that the first property, the middle oxide layer extending less than the length between the first junction and second junction;
a top oxide layer having the first oxide property and extending the length between the first junction and the second junction; and
first and second polysilicon inserts defined in undercuts between the bottom oxide layer and the top oxide layer in a level of the middle insulator layer, the polysilicon inserts positioned beside the middle insulator layer and extending respectively to the first junction and the second junction.