TEOS and Ozone Atmospheric Pressure CVD of Borophosphosilicate Glass Films Using Triethylborate and Trimethylphosphate

Abstract

Borophosphosilicate glass (BPSG) films were deposited using tetraethoxysilane (TEOS), triethylborate (TEB), trimethylphosphate (TMOP), and ozone at atmospheric pressure. A uniform distribution of borate was obtained throughout the thickness of the film using TEB instead of trimethylborate (TMB). The deposition rates were characterized as functions of dopant gas flow rates, deposition temperature, and ozone concentration. Both dopants enhanced the deposition rates. The deposition rates did not show ozone concentration dependence. The typical deposition rate was as high as 0.2 μm/min. The borate and phosphate contents were characterized as functions of dopant gas flow rates, and deposition temperature. They ranged from 8 to 15 mole percent (m/o) for borate and from 3 to 8 m/o for phosphate. The film stress was as low as 1×109 normaldyn/cm2 (tensile) when deposited at 400°C with 4% ozone and relaxed to −0.7×109 normaldynsol;cm2 a week after deposition. The film shrinkage was minimum (5%) at 400°C, and decreased with increasing ozone concentration. The step‐coverage of an as‐deposited film was superior, hence, the film reflowed smoothly even after the low temperature (850°C) annealing.

Review—Mechanical Stress in Chemically Vapor Phase Deposited Boron- and Phosphorus-Contained Silicate Glass Thin Films: A Review

“…There is a stress relaxation effect revealed in as-deposited BPSG films stored in ambient condition. 4,18,27,30 This means the stress values decreased gradually to lower values during the film exposure to ambient conditions. This effect corresponded to the well-known moisture absorption phenomenon for BPSG films discussed earlier.…”

“…This data array covers almost four decades of related publications. [2][3][4][5][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30] Different vapor phase deposition techniques with different chemical reactants were used for the film deposition.…”

Characteristics of CVD silicon oxide films: Effect of discharge form on formation and properties of films

“…The thermal CVD (chemical vapor deposition) method is widely used as a production method employing the chemical reaction with ozone, especially under atmospheric pressure using TEOS (tetraethylorthosilicate) as a silicon source, so as to ensure a good step coverage [1][2][3]. Various modifications of this CVD method have been tried [4,5], but the step coverage obtained is barely adequate. The necessary step coverage can be found by using complicated multiple processes [2,6].…”

Process Characteristics for Subatmospheric Chemical Vapor Deposited Borophosphosilicate Glass and Effect of Carrier Gas

“…3 Using current chemical vapor deposition (CVD) technology, BPSG films can be deposited either by silane 3 or 0O-TEOS (tetraethylorthosilicate) based BPSG processes, with TEOS/0O BPSG film showing much better step coverage than silane BPSG film. 2 Among all the technologies, subatmospheric (SA-) CVD BPSG using triethylphosphate (TEPO) and triethylborate (TEB) as dopant sources has been studied extensively to yield superior film quality and improved reflow capability. 4 However, due to the process complexity, very little is known about the reaction mechanism for TEOS/0, BPSG, even though some modeling has been done for the undoped silicon glass (USG) using TEOS/03 chemistry.…”